I ordered my first ever mac (a decked-out 17" PB as BTO) on December 21, not having known about the pending update. When I later heard the rumors of powerbook updates, I was pretty upset with myself for not having researched the topic enough. But once I heard that there won't be a significant upgrade, and after a bit of reassurance from a few members here, I was much happier, and now am eagerly looking forward to its arrival.
My needs might be a little more demanding that most people's: I'll mainly be using mine to do real-time image analysis in a hospital environment as part of my masters of engineering, as well as the odd powerpoint presentation, a bit of lounge web surfing, a hint of FCP, and some Java development on the side. And while it's always great to throw as much processing power at problems such as these, I don't feel that this minor improvement would really make much of a difference. I'm not particularly concerned about the pricing either, since it'll all be covered by a grant, so I can spend my money on making the switch at home as well.
In fact, my biggest concern now is time -- I have to learn a whole lot of Quicktime and AltiVec programming as quickly as possible, so I can port my existing application over from it's current DirectShow implementation with minimal fuss. And I haven't heard anything back from my local reseller yet, who I put the order in with (cheaper than Apple.com.au, and free Airport Express), which has me somewhat concerned, although I technically can't get the education discount yet since my application hasn't been processed by the university yet. I just hope it all comes soon... I can't stand the waiting any more 🙁
Plus, in a somewhat pessimistic view: when your powerbook suddenly dies, you might get lucky and receive the new model as a replacement.
I hope this helps you somewhat. It's certainly helping me to overcome my Product Waiting disorder 😱