Not everything's optional
You have control over your talent build. If you want to pick up Denounce and Blazing Light for a hybrid build, you're allowed to do that. The trouble is that most of us are looking to maximize one aspect of our paladins, and for holy paladins, that's usually healing. We'll sacrifice any amount of offensive potency to boost our healing output, and our talents should reflect that. There are several talents in the holy tree that are pretty mandatory due to their function or potency, and you really don't want to build a holy spec without them. There are plenty of points left over for us to flex around wherever we desire.
Spec for your encounter
I tell rogues on a regular basis to "spec their weapons" and choose whatever build makes the most sense based on their gear. With healers, we want to maximize our performance on the encounters that affect us the most. There's no point in building a primary spec for running regular dungeons if you're raiding, and your focus should be optimizing your raiding build. It's difficult to look at healing from an objective viewpoint, and you shouldn't try to. Look at healing from your perspective and choose your talents to complement your environment.
Protection and retribution favorites
While we're locked into putting 31 points into the holy tree, we're still allowed to drop points into the first couple of tiers of protection and retribution talents if we so desire. Divinity in protection and Crusade in retribution are both considered to be mandatory talents and I haven't seen anyone skip either talent. Divinity is amazingly potent for only three talent points, and Crusade helps to buff our signature spell, Holy Shock. Eternal Glory in protection is also very popular, although it was recently discovered that the proc has a 15-second cooldown that reduces its value. I've been seeing a lot of paladins only putting one point into EG now.
Improved Judgement is the other non-holy talent that I see people picking up, although its utilization varies. Some people swear by two points in it for our long-range Judgement attack, while others put one or no points into the talent. If you're playing close to the boss then the talent is wasted, but I find myself standing behind the ranged stack to hit them with Light of Dawn quite often. We can also add range to our Judgement by picking up Enlightened Judgements, which comes with a few perks on top of the range addition. How you flex your points between EJ and IJ is up to you, and I've seen every combination. I recommend at least one point in EJ to give you the hit chance necessary to land your attacks regularly, and this will become even more important when we learn Rebuke in the upcoming patch.
Word of Glory talents are falling behind
I originally loved the idea of picking up Last Word to give our Word of Glory a boost when used on low-health tanks, but in a raid, it's so much easier to use Light of Dawn instead. If a tank is low on life, I am already casting Divine Light. Many other paladins have had the same revelation, and so most are putting but a single point into Last Word just so they can move down the tree. Glyph of Light of Dawn is fairly mandatory for any raid healer, and even with Glyph of Word of Glory, I don't find myself casting it that often. I am seeing a lot of holy paladins only putting the one mandatory point into Last Word and just one point into Eternal Glory. The WoG talents simply aren't that great.
Blessed Life vs. Tower of Radiance
Tower of Radiance went from being a core of the holy paladin healing paradigm to a second-class talent that rarely sees use. The only real use case for ToR is if you're going to be using a lot of Divine Lights. I like to use two Divine Lights, weaving in a Holy Shock, and then using a Word of Glory or Light of Dawn with my three holy power points. It helps reduce our mana usage when we're required to use Divine Light to keep the tank up, and I've found it to be very valuable in these situations. Even without using Holy Shock you can still make every fourth cast a Word of Glory to avoid running out of mana.
ToR's next door neighbor is Blessed Life, a very underrated talent. I originally figured it to be a PvP-only talent, where it certain shines, but I've found BL to be very valuable in raid situations. We take damage all the time and BL helps us generate extra holy power points we can convert to finishers easily. After looking through my World of Logs reports, it's clear that Blessed Life is contributing significantly more holy power points than Tower of Radiance. While I don't suggest skipping ToR, some paladins are dropping it.
Paragon of Virtue: A rare luxury
Paragon of Virtue is a talent that I didn't like until I actually tried it. I get that it reduces the cooldown on Hand of Sacrifice, and that's great. HoSac is one of the few "external" tank cooldowns still available, and Protector of the Innocent ensures that we won't die while sharing some of the tank's damage. There's value there, especially for progression raiders facing heavy-hitting bosses. The Avenging Wrath cooldown reduction is equally important as it allows us to to heal through heavy damage phases or to compensate for Divine Plea.
The Divine Protection cooldown reduction is something a lot of players glance over, but it's actually quite powerful. It allows us to reduce all damage taken by 20% for 10 seconds every 40 seconds, meaning we can have it up 25% of the time. If timed properly, you can reduce your incoming damage significantly, and since it doesn't activate Forbearance, there's really no reason not to use Divine Protection. Start using it more often! You can even pick up the Glyph of Divine Protection to allow you to mitigate 40% of incoming magic damage (at the cost of the physical damage reduction). On fights with tons of magic damage being dealt, this glyph is incredibly clutch.
The Light and How to Swing It: Holy helps holy paladins become the powerful healers we're destined to be. Learn the ropes in Cataclysm 101 for holy paladins, study the new balance between intellect and spirit and learn how to level your new Sunwalker. Tanking is a job, DPS is a craft -- but healing is truly an art.