Just a quick warning to anyone looking to upgrade to the upcoming release of Eclipse 3.6 / "Helios" and uses the HTML Editor or Web Page Editor. As of all the release candidates, including RC4 of Classic with the WTP editors installed and RC3 of the JEE / "Eclipse IDE for Java EE Developers" package, spell check is broken. Quite simply, HTML content is no longer being checked for misspellings. The spell checking is working as expected in 3.5.2.
I reported this in bug 316025. I'm not sure if it can or will be fixed before the official release, but it is a fairly significant issue in my opinion. If this issue will affect you, please sign-in to Eclipse's Bugzilla and vote, or otherwise contribute.