I hear mineral oil brought up in discussion so many times, but these sort of solutions are surely just more trouble than they're worth.  The heat captured still has to go somewhere - if air cooling isn't enough, then waterblocks are a far more sensible and proven solution if you insist the stock cooling is inadequate for your needs.

Yes, but what about overclocking I hear you say.  450MHz dare I say it, is a fantasy figure.  Theoretically possible according to Avalon but based on pretty much all real world overclocking experiences the absolute maximum is typically impractical for either stability, safety, energy consumption, chip longevity etc..  If the majority of Avalon chips were capable of this, for what conceivable reason would they have limited their clock to 285 MHz in their own units.

What's really most important is getting boards in hands.  I wouldn't want to see any attempt to build in exotic overclocking abilities stand in the way of that.  Sure, a modest overclock to mid-300s would be awesome but I reckon after that you're into severely diminishing returns.  There's also the warranty issue - Burnin offers a 2 year warranty.  What about the fools that try 450Mhz on air cooling?