Well, xVim v0.2 is out. It now supports Visual Mode, though some command are still not implemented yet.
What is xVim
What is not xVim
Any way, the difference between Vim and xVim is that, Vim is an full featured (not-good-looking?) editor, while xVim is just a plugin.
That is to say, features belonged to editor (e.g. bookmarks, tags, and anything sounds complicated…=, =) will not be implemented in xVim.
What app is supported