I saw Marc Andreessen present at an Internet event in London about 9 years ago and I wanted to not like him as those were the days of Netscape vs. IE and I was helping get IE4 out to market. He came across as a likeable bloke though and quite shy as I remember and I've always read his stuff be it interviews or articles. I'm now an avid follower of his blog and he (and perhaps Seth Godin) are the only people who write really long blog posts that I bother reading.
This recent post from Marc on Internet plaforms is a bit geeky/techie at times and I probably need to read again to "get it" but as I read it first time I found myself nodding in agreement. I'm not sure I agree with the level 3 platform vendors but I'm sure he will not lose sleep over that. If nothing else this is worth a read for a definitive view of PLATFORM - perhaps the most overused term in IT.