I just downloaded the new version of Firefox and so far, I’m very impressed. I was disappointed that in breaks several extensions that I use on a regular basis, including:

• Bloglines Toolkit
• Copy Plain Text
• ChromEdit
• Greasemonkey
• SpellBound

None of them are deal breakers–well, SpellBound would have been but reinstalling the libraries fixed it. Living without the others will be a pain, but I’ll cope. And one of the things that will help me cope is the new del.icio.us extension! It’s awesome!
Update: Ken hipped me to two new extensions that have become indispensable as well. The first is NoScript which allows you to have Firefox only run JavaScript from whitelisted websites. The second is SessionSaver, which I can’t believe I lived without; it allows you to have your current session saved whenever Firefox is closed, and then restores that session when you restart. Awesome!