Here's a list of all the proprietary stuff Apple has shoehorned into the "best Mac it has ever made", the MacBook Pro with Retina display (henceforth referred to as "MBPwRD"), taken from the iFixit teardown:
Irritating pentalobe screws, which don't stop anyone determined to disassemble their MBPwRD but mean you need to waste time buying special drivers on eBay.
RAM soldered to the motherboard, as we all suspected. No ability to upgrade it after purchase. I couldn't find anywhere on apple.com that makes this limitation clear to shoppers, either. That strikes me as disingenuous.
Proprietary -- though removable -- SSD. We can hope for third-party upgrades in the future. Impressively, it's not even the same as the other new proprietary SSD in the new MacBook Air, which is also not the same as the one in the old MacBook Air. Standards!
Battery glued firmly into the case, making removing it potentially hazardous (lithium ion cells can explode if pierced).
Battery glued over the delicate trackpad cable, which you run the risk of breaking if you do get the battery out without killing yourself.
Display assembly permanently fused together, with no protective outer glass sheet. If you have to replace any part of it (e.g. a scratch on the outer surface), you have to replace the entire upper lid, at great expense.
Overall, iFixit gave the machine a dismal 1/10 for repairability.
I don't like this one bit. I didn't care for the MBA's approach to sealed-in no-user-serviceable-parts computing, but I can just about see the justification on a product level when you're talking about a relatively low-cost, low-powered computer aimed mainly at consumers. I can also understand that most of these elements are necessary to achieve the MBPwRD's svelte lines. Removable RAM or a standard 2.5" SSD or even battery screws would all take up more room inside the case.
However, the higher end market feels different to me. My last MacBook Pro saw a little over 2.5 years as my primary computer, and I would expect no less of any computer I was paying in excess of $2200/£1800 for. In that time, I upgraded the memory once, the hard drive three times, and replaced the battery once. None of these options would be available to me with a new MBPwRD. SSDs, batteries, and RAM can degrade or fail in time -- is a $349 AppleCare purchase a hard requirement now? What if I want to keep my MacBook longer than the three years coverage AppleCare offers?
This would be a smaller problem if it wasn't for Apple's upfront upgrade costs, which could be reasonably described as daylight robbery. It charges $200 to upgrade the RAM from 8 GB to 16 GB -- that costs around $85 on the open market. Changing the SSD from 256 GB to 512 GB is $600 (including a modest CPU upgrade from 2.3 GHz to 2.6 GHz). Upgrading from 512 GB to 768 GB is a further $500. Meanwhile, in off-the-shelf land, an entire top-of-the-line 512 GB SSD can be had for $415 today, with 256 GB models around $280.
If this is the price you pay for a thin laptop, I want no part of it. The MBPwRD is 21% lighter and 25% thinner than the corresponding non-Retina-display model. Those aren't life-changingly better numbers, and to my mind, they aren't enough of an upgrade to justify all the features Apple has removed to make them possible. This new laptop isn't a MacBook Pro at all; it's a MacBook SuperAir.
Now the interesting part comes, though: how many people agree with me strongly enough to avoid the MBPwRD? The opposing view: how many will dismiss my concerns and buy the MBPwRD for the (apparently fantastic) display and improved portability? What would have happened if Apple had offered a Retina display on the older, thicker chassis? And worst of all: what do I do in a year or so, if (as seems to be widely expected), the "classic" MacBook Pro disappears and it's soldered RAM all the way down?
Responses on this topic: Mashable's Christina Warren offers her take on the serviceability issue.