Although the team's intentions might have been good, the new help system in Visual Studio 2010 is a huge step backwards (more like a cannonball-shot-kind-of-leap really) from the one we all know (and love?) in Visual Studio 2008 and 2005 (and heck, even VS6).
Its biggest problem, from my point of view, is the total and complete lack of the Help Index feature: you know...the thing where you just go and type in what you're looking for and it filters down the list of results automatically. For me this was the number one productivity feature in the "old" help system, allowing me to find stuff very quickly.
Number two is that it's entirely web based and runs, by default, in the browser. So imagine, when you press F1, a new tab opens in your default browser pointing to the help entry. While this is wrong in many ways, it's also extremely annoying, cleaning up tabs in the browser becomes a chore which represents a serious productivity hit.
These and many other problems were discussed extensively (and rather vocally) on connect but it seems MS seemed to ignore it and opt to release the new help system anyway, with the promise that more features will be added in a later release. Again, it kind of amazes me that they chose to ship a product with LESS features that the previous one and, what's worse, missing KEY features, just so it's "standards based" and "extensible". To be honest, I couldn't care less about the help system's implementation, I just want it to be usable and I would've thought that by now the software community and especially MS would've learned this lesson.
In the end, what kind of saddens me is that MS regards these basic features as ones for the "power help user". I mean, come on! I mean a) it's not like my aunt's using Visual Studio 2010 and she represents the regular user, b) all software developers are, by definition, power users and c) it's a freakin help, not rocket science!
As you can tell, I'm pretty pissed. Even more so because I really feel that the VS2010 & co. release really is a great one, with a lot of effort going into the various platforms and frameworks, most (if not all) of them being really REALLY good products. And then they go and screw up the help! How lame is that?!
Anyway, it's not all gloom-and-doom. Luckily there is a desktop app which presents a UI over the new help system that's very close to what was there in VS2008, by Robert Chandler (to which I hereby declare eternal gratitude). It still has some minor issues but I'll take it over the browser version of the help any day. It's free, pretty quick (on my machine ;)) and nicely usable. So, if you hate the new help system (passionately) like I do, download H3Viewer now.