Not bad, didn't know 2.8's were available...
I'm still using a 1.8a haven't changed it in over 6 months
The most I've overclocked it to with good stability is 2.47 but I can't be bothered with the fan noise and watercooling is still just an expense I can't justify.
The thing with LN2 is that it's temporary, overclocking is all about etting stable high speeds not making a machine boot at the highest possible. Still I remember when - another Finnish dude no doubt - sent the first Northwood to 3.7Ghz, probably the first time anyone took notice of the P4 in overclocking circles.
Notice Intel did this same test - ish - but only use watercooling, just shows what the core is capable of.