You can play the waiting game your whole life when it comes to technology. In the big picture, what's the point?
I bought my old Macbook Pro RIGHT when they were first released. I used that thing all the way up until I bought this new unibody MBP two weeks ago. My old one got me through 3 years of college and 1 year into the real world creating marketing and advertising campaigns. It worked perfectly for everything I needed, from Word to Photoshop to all sorts of video editing. I even turned around and sold it for $1,300 four years after i bought it!!! The resale value on these things is absolutely amazing.
Sure, new ones were released after I bought mine. But the changes were never enough to justify replacing it. Until these new ones were released, that is. I will admit that this new one blows my old one out of the water. but with 4 years of newer technology in it, i would expect nothing less.
Rambling aside, I say go for it. You only live once!