Nokia 770 has ARM cpu (arm926tej core) running at 250MHz. Some people think it is very slow when compared to much higher cpu clock frequency used by intel xscale processors used in some competing devices. I just found the following link, and it makes me wonder whether cpu performance difference is really that huge:
http://slashdot.org/comments.pl?sid=34661&cid=3750803

It somewhat resembles pentium4 vs. athlon competition to me (higher efficiency vs. higher cpu clock frequency). Any thoughts?

It's definately powerful enough for what it's meant to do. Compared to the PSP's 333 MHz (222 MHz technically), it holds its own quite well in the multimedia area. Of course the 770 isn't primarily a gaming device either.

If you're asking weather it can handle features like Java and Flash, I think it's still too early to tell what the limitations there are for the current hardware. It's safe to say there is still room for growth through software and memory optimization..

Here is overview of cpu core used in Nokia 770: http://www.arm.com/pdfs/DVI0035B_926_PO.pdf
Just thought it might be interesting to know instruction timings for those who are interested in assembler optimizations if they did not find this pdf themselves yet

A few references related to arm cpu performance.

Instruction timings and optimization guide for ARM9E: http://arm.com/pdfs/DDI0222B_9EJS_r1p2.pdf
Instruction timings and optimization guide for ARM11 (used in OMAP2): http://arm.com/pdfs/DDI0360C_arm11mpcore_r0p3_trm.pdf
Instruction timings and optimization guide for Intel XScale: http://download.intel.com/design/int...e/27347302.pdf
Instruction timings and optimization guide for Cortex (used in OMAP3): http://arm.com/pdfs/DDI0337C_cortexm3_r1p0_trm.pdf

Comparison of ARM7 and ARM9: http://arm.com/pdfs/comparison-arm7-arm9-v1.pdf
Comparison of ARM9 and Cortex: http://arm.com/pdfs/13128.pdf
I did not find a comparison between ARM9 and ARM11 on arm website, maybe it does not exist just because ARM11 is slower than ARM9 per clock Though ARM11 has higher clock frequences, so overall performance is better.

Well, ARM9E used in Nokia 770 is quite a good core and is faster than ARM11 and XScale per clock. And according to documentation, Cortex core is really impressive, but probably it will take quite a lot of time before we see OMAP3 in one of the Nokia 770 successors.