kuebk well that is always your personal preference with what you are comfortable with.
Heck, I ran my E6600 for over a year with 1.65vCore & 1.60v FSBT/VTT no degrading what so ever. Ran my XP2500+ with 2.0v back in the days. Have yet to kill a CPU. MOBOs, well thats a different story...

For me 1.48vCore is fine since I'm watercooling and my temps are in check. Still going strong after 6 months.
Although I have to admit that I did a remount after lapping my CPU, my sensor is stuck at 18°C no matter what I do.

I stumbled across a thread of a guy here testing several 45nm CPUs at crazy voltages like 1.8vCore, 2.0 PLL 1.6FSBT/VTT running stress tests 24/7. At some point he gave up because nothing happend. But I can't seem to find the thread atm. Maybe someone here can link you.

A-Grey, sorry I haven't gotten round to testing different skew settings on CPU & NB yet, work is keeping me rather busy, but I'll keep you posted.