According to yahoo finance Berkshire trades at 1.52 times book value. This is near its historical bottom and below its average for the last 10 years. See this post on the chucks angels group for the calculations.
I own some brk-b (class B stock ) of berkshire hathaway and feel that its CEO Buffett is finally finding good opportunities to invest the tens of Billions or so in cash he had lying around into higher returning stocks. This may drive returns higher than the SNP 500 by a few points over the next decade.
Buy and hold investors, especially those who are heavily taxed should give the stocks a look. Berkshire does not pay dividends so you only pay taxes when you sell.
I also recommend the Chucks Angels group for people wishing to do more research on Berkshire Hathaway.