I have never been to an Excel Conference - I have been to many work conferences (read junkets) - what is expected of the 2008 conference (will there be an entry exam?)
If so, I have been to the UK version a couple of years back. Andy Pope & Bob Phillips were presenting.
To be quite honest, I didn't learn much, but that wasn't the reason I was there - The outside sessions over dinner & beers were far more interesting - got to meet a fair few guys who I had only ever communicated with over the net... and get pissed too... thoroughly enjoyable