Well lets see...
Processing Power
I upgraded from a 550 MHz AMD-K6 II laptop, so I think the performance is about what I expected, twice as fast as my previous laptop. One thing that I've gotten used to is the speed of the internet...IE on the PC laptop is still faster than Safari on the Mac...which is annoying.
As for other tasks, I find the performance just fine, fast enough for what I have to do.
Multitasking
I'm using Codetek's VirtualDesktop, so I am a bona-fide multitasker...right now I have 12 applications open in 10 virtual moniters. I find that sometimes the computer will lock up and I get that spinning beachball, but if I'm patient the app will open. I only have 512 MB of ram, so I really should upgrade soon. I find the multitasking capabilities just great.
Graphics
I'm not a gamer, and the only game I currently have is Riven, and it plays just fine.
DVD Playback
Goods: The screen...large enough that I sometimes have to pan my eyes to see the entire movie from where I'm sitting. LOTR DVD played beautifully (1:2.35 aspect) and the black bars were noticible but not bad. The documentary on the extended DVD (9:16) have the black bars on the top and bottom so small that you don't even notice them. Picture quality is great, I love it. Not jerky at all...not even a glitch during over the entire 4 DVDs.
Bad: The drive is a bit louder than I'd like...if I use the laptop speakers (which sound great), I can hear the DVD drive...so I end up using headphones.
Burning
After burning several CDs at 16x, I must say that Toast is a bit misleading. Sure initially it shows abour 4 minutes to end of burn, but the time doesn't count down by the seconds...in real time it ends up being about 6-7 minutes or actual 10-12x burning. I"m not complaining at all..it's still faster than 8x.

Haven't burned DVDs just yet, but I plan to this week.
Battery Life
These are from 10.2.5: When running at 100% CPU, I have slightly over two hours, when playing a DVD, i have a bit over 2.5 hours, and when running light tasks I can get close to four hours. Interestingly OS X.2.5. allows me to get a bit battery life than with X.2.4.
Wireless
I find that reception is great...I can access points over 100 ft. away (?), through walls...either way it's impressive.
Other
The computer is still impressive...the fan is on a bit more than before, and a bit louder than expected. It's still an impressive machine...