I don't think they'll be redoing the PR's too much. It's enough confusion as is. It's be better to just stick with the same system. Plus barton isn't a completely redesigned chip. It's like, there the XP's, .13 XP's (t-bred), then .13 XP's with a fat cache (barton). MHz-wise a barton should be able to do whatever the t-breds can, and I'm sure that by the time the .13 process matures (i.e. better steppings) we'll be OCing those chits like mad.
Just think, AGKGA was'nt all that great for overclocking. With a vmod I still only got it 190 MHz over spec, like 150 without the vmod. Now look at the AROIA and AGOIA steppings. People get 400-500 MHz OC's with the 1600's and ~350 with the 2000's and up. Hell, some people get the 1600 to 2GHz, that's a 600 MHz overclock ala P4 1.6a. But 600 MHz on an XP is worth a whole lot more than 600 MHz on a P4...
I think once the t-bred matures we'll see some good things, but that small die size is gonna hurt on the heat tip. Once those bartons come around I think we'll see some great things! Bigger die, bigger cache, high MHz, what's not to like?
--Illah