Q: Does this mean I can now use JRockit with any Java application?
A: Yes, under the same terms as you currently use the Oracle (Sun) JDK. You don't need to inform us and you don't need to pay anything.
Come-on: Give your heart a kick: Let's go: I've written a very short howto starting over with JRockit and GlassFish. Start using it today! :)
Q: I am a developer, does this mean I can now use JRockit Mission Control for free?
A: Yes, there is no cost for development use. See the license for details.
Wow .. man, this is great news in general: I personally love the JRMC. It's the most complete and ootb solution for getting your JVM under control. Nothing against VisualVM or even the JConsole, but ... JRMC plays in a league of it's own.
In general Oracle seems not to recommend moving to JRockit today. Even if you could. I guess, they are right. Everything in Henriks post seems to indicate, that they are willing to have the first converged version out with the Java SE 7 / OpenJDK 7 release later the year.
Anyway, if you are in need for some very effective memory management and a high speed JVM. You finally have it! Great!
And don't forget to look at the JRockit bible: "Oracle JRockit - The Definitive Guide". I have written a review about it a few months ago and I am still getting goose skin thinking about the hard time this book gave me ... but it was worth it!