The fire started when Linus Torvalds wrote a reply to a mail in the Linux kernel mailing list where he pondered on Sun Microsystem's true intentions in willing to release Solaris under a GPLv3 licence and how the rise of Linux has hurt Solaris and how Sun doesn't want to help Linux.
In his own words, this is what Linus said (and I quote parts of the mail):
They may like open source, but Linux _has_ hurt them in the marketplace. A lot.They want to use Linux resources (_especially_ drivers), but they do *not* want to give anything back (especially ZFS, which seems to be one of their very very few bright spots).So to Sun, a GPLv3-only release would actually let them look good, and still keep Linux from taking their interesting parts, and would allow them to take at least parts of Linux without giving anything back (ahh, the joys of license fragmentation).
Jonathan Schwartz the president and CEO of Sun Microsystems has written a reply on his blog to Linus Torvalds explaining Sun's true intentions and why it is taking so long for Sun to release Solaris under GPLv3.
But most of all, from where I sit, we should put the swords down - you're not the enemy for us, we're not the enemy for you. Most of the world doesn't have access to the internet - that's the enemy to slay, the divide that separates us. By joining our communities, we can bring transparency and opportunity to the whole planet. Are we after your drivers? No more than you're after ZFS or Crossbow or dtrace - it's not predation, it's prudence. Let's stop wasting time recreating wheels we both need to roll forward.
You may also be interested in reading the comment made on Jonathan Schwartz's blog by OpenBSD founder Theo de Raadt.