From what I understand, the XIAs are the newer Athlon chips that are much better for OCing. If I were to get an Athlon 1.33Ghz, am I guaranteed a XIA since the 1.33Ghz chips are fairly new?
Yes- you are guarranted to get a AXIA. There is no way AMD would sell a 1.33Ghz chip on the old core- it wouldn't run stable enough. Hell, people getting 1Ghz athlon's are getting the AXIA cores now. I ordered a 850mhz Duron a month ago and it's a AXIA core.
Palomino is a whole different core all together. It can supposedly run cool with just a heatsink. AMD was questioned about that rumor and they said "it runs REALLY cool". The 1.3Ghz AXIA's can hit 1.5Ghz with no problem.
From what I understand, so can the 1GHz. Are there 1GHz "B" AXIAs? I ask because the only 1GHz AXIAs I found were "C" chips, and the "B" would go to 1333 simply bu changing the FSB to 133, and 1500 by changing it to 150, with no multiplier adjustments.