I must say that I really like Mylyn. Besides all the issue tracker integration, the task context features are great. Today I got a "ahh, this is to good to be true" moment.
I was working on my clear case plugin for Hudson, and was going to fix a feature request I entered two months ago. So I activated the task, and suddenly two files was opened in the editor. The caret was moved to the method that was going to be involved in fixing the feature. Apparently Eclipse has improved recently and it knew how to fix the feature before I knew.
Then it dawned on me that I had started looking into fixing the feature two months ago, and thats why the task context already contained the two files. I just picked up where I left two months ago, and could continue working on the feature request within minutes. That is great functionality that doesn't intrude on the user, it just works!
So if you are using Eclipse and haven't tested mylyn, start using it today and you will be happy in two months! (and the time in between!)