No Apple is 42% of Berkshire's investment portfolio. Berkshire's investment portfolio is roughly 1/3 of the value of the company. The majority of the value of Buffett's baby isn't the stock it is the 40 odd companies he owns outright.
Everything from railroad giant BNSF, to Geico insurance, small guys like See's Candy, Dairy Queen and hosts of others.
A couple of days before the bottom of the 2009 market, I wrote post on here detailing why I thought Berkshire was a super safe bet, and was all but certain to be a lot more valuable in a couple of year than it was currently trade for. Berkshire is my largest individual holding
I think Berkshire valuation is starting to get attractive. But, I'm no where near calling a bottom for Berkshire yet.