Asset Allocation, Part 1

I will start the process of documenting my asset allocation plan with my AA at the beginning of 2007. I have made some changes to it since then and I will try to explain my thought process behind the changes and the things that are on my mind right now. First the AA at the start of 2007:

#	Asset Class	Current	Target
1	US Total Market	18%	15%
2	US Small Value	11%	12%
3	Intl Larget Market	15%	15%
4	Intl Value (Hedged)	13%	12%
5	Emerging Market	10%	12%
6	Total US Bond	4%	4%
7	TIPS	5%	5%
8	Short Term Bond	5%	5%
9	REITS	10%	10%
10	Alternative	10%	10%

At the start of 2007, my alternative asset class was invested in the following:
BRK-B : 6%; Commodities - 3%; MSFT - 1%;