Okay, maybe 4 years was pushing it a bit
Look, no offense here ok. There are already systems that compete with a 2GHZ PIV for the money your talking about. All of the current PowerMacs will compete with a PIV and smoke it in most apps.
I'm not trying to start an argument but I know for a fact the entry level G4 can match at least a 1.8Ghz Pentium 4 for what I spend most of my time doing. It's just a few other things where it would lag behind.
For protools LE, the mac stacks up pretty well against a PC
G4 800 : 135 plugins
P4 1.8Ghz : 125 plugins
This is from the Dave C test on the Digidesign site, I've done it myself and managed only 30 plugins with all the tweaking I could do to get them. I know I'm in for treat when I buy a new mac!
I was over-exagerating a little on the 4 year thing, I just know that for my main application, Protools LE, my beige G3 is slow but (just about) usable, I don't doubt that if I had a 1Ghz+ G4, It would easily last 4 years at a push if it took me that long top save up for a new one. I've had my beige G3 for nearly 4 years and I've only begun to feel the lack of speed over the past 18 months or so. To be honest, I'd really be looking at a new mac every year if I could afford to upgrade that frequently.
Seeing as photoshop is the main benchmarking application Apple use, here's some numbers that prove how slow the entry level G4 is for photoshop:
It's taken from
Barefeats
1.8Ghz Pentium 4 : 59 seconds
933Mhz G4 : 72 seconds
There were no comparable results for the 800Mhz model so here's the results from another test on the site using the same benchmark action:
933Mhz G4 : 71 seconds
800Mhz G4 : 101 seconds
from that you can see that a 1.8Ghz Pentium 4 is around 70% faster for photoshop than an 800Mhz G4. Again, I'm not trying to start an argument here, You can prove anything with facts and the old "reality distortion field" stuff doesn't work on me
I just think whatever Apple bring out at MWNY, people who've held out a few years on upgrading will be pretty happy with the performance they'll get out of it.