For example, say I have 2 projects, P1 and P2 which are identical except from different cvs branches. If all I have open is P1/Foo.java and I go to open Bar.java, the Open Type dialog does not respect the fact that I'm currently working on P1, and I have to navigate to the right project within the dialog instead of simply hitting enter. This is not only a waste of time, its also very easy to mistakenly open/edit the wrong file!
I would much rather have the the default project selection be the same project as the project for the file I currently have focused. See the eclipse bug I have open on this issue.
Anyway, this problem annoyed me one time too many, so I ended up writing replacement dialogs that do the right thing. These are basically copies of the eclipse classes into my plugin with some tweaks - gotta love open source =). They'll be part of my sunshade plugin suite for the 3.1 release. The old dialogs will still be there, but you'll be able to map the old key bindings to my replacements if you wish. The Open Resource dialog replacement is intelligent and makes the default project selection be the current project, but you can navigate to other projects if you wish. On the other hand, Open Type Dialog limits the entire view to the current project - its seriously complex and I haven't dug in far enough to figure out how to get it to work like Open Resource does. Till then, I map ctrl-shift-t for OldOpenType, ctrl-shift-p for NewOpenProjectType, and ctrl-shift-r for NewOpenResource - you may like to do something similar.
I haven't checked them into CVS yet as I wanted to try and get OpenType working correctly. However, if you are as annoyed with the old behavior as I was, feel free to comment and I'll accelerate things. I'll probably submit a patch to eclipse as well, but who knows when that will be accepted, and I wanted to benefit from the new behavior now =)