The Witcher 2 has been out for over a week now, and there's been a lot of talk about its difficulty and learning curve in reviews, on forums, and so on. Allow me to be straightforward and say I completely do not understand it.
I'll start with the Penny Arcade comic. Like many, I'm a fan of these guys, but this is completely misleading.
Tycho writes, "It has tooltips that pop up from time to time, but if you’re under active assault by a dragon maybe you aren’t looking at that."
All needed abilities, techniques, and controls are explained quite clearly via these tooltips: click the mouse to attack, press E to block, Q to use signs, R to use bombs and traps. Not looking at it? Hit J to review all tutorial tooltips and other useful information, as it tells you (it doesn't come up during an action sequence, so there's no excuse there). Nevermind the 35 page manual, which explains all this stuff and more in explicit detail.
On the topic of difficulty, well, TW2 doesn't baby you. After the initial main tutorial section, you're thrown into your first tough fight (1:35 in the video below). The aim here is to show you all the ways you can die if you don't use your head -- attacking groups carelessly, leaving yourself open to flanking, attacking units with shields without magic or flanking, etc. are all good ways to get yourself killed.
It's at this point you'll either throw your hands up and say "that's it!" or look at it as opportunity to improve. Choosing the latter and with some moderate effort, you'll see rolling, bombs, traps, signs, flanking, blocking, and more options and techniques are at your disposal at any given moment. Use them all. This stuff isn't just here for show so the developers could brag about a bunch of needless features in interviews: use them!
After this fight, consider yourself graduated. The game will challenge you many times thereafter, but mostly you'll know how to handle it, or will soon after. And the second time you play through, even that first 'tough' fight should seem like a piece of cake.
For those that don't look at it as an opportunity to improve, that's fine, just don't whine about it the whole way through masochistically: turn it on easy -- that's what it's there for. And after easing yourself into the game on that difficulty, if you become quite comfortable, you're able to bump it up to Normal or Hard at any time if you so please.