Personally, I've never had a problem with respec costs. Not counting the class respecs I've gotten free as a warrior, mage, priest, hunter, and shaman, the only time I've ever respecced was to bring my Frost mage back to a Fire build (not that it helped-- generally I'm a player that plays in plate, not cloth). So at first glance, this idea doesn't sound very good. Especially with the changes made lately (respecs are now decaying over time, 5g/month to a minimum of 10g), respecs aren't that big a deal. They're there if you need them, but they're expensive enough that you want to do your research before choosing where to put those precious talent points.
But Vengal has an interesting point as well: if respec costs were done away with, you could respec nightly. Be PVE one day for soloing, be PVP the next for a tour in the BGs, and then go raid spec for a night with your guild. He says respec costs aren't a punishment for people who spend their talent points unwisely-- they're a punishment for people who want a change. (Personally, I haven't played Guild Wars, but I believe that's how that game works-- you can change talents at will and customize your class whenever you want.) On the one hand, that would lead to new levels of competition in the different play types-- if everyone in the BG was specced for PVP, you have to think battles would be extra-spectacular to play in. Then again, letting anyone respec at any time would inevitably turn us all into cookie-cutter play types. There would be no real room for personal customization or playstyle-- your guild would expect you to be raid-specced if you were going on a raid (ahem-- much the way gear works right now, but that's another discussion).
There's a few more interesting ideas in the thread, too: Maybe only the last twenty talent points could be respec free (or the last ten, since the expansion will take us to 70). Blue hasn't made an appearance in the thread as of this posting, but it's something they might consider carefully: are respec costs punishing players who want to be more versatile?