As bug 542920 has been fixed, I've released a new version of the Vala plugin for anjuta.
Highlights for this release :

* Now compiles without patching anything, you'll need vala 0.5.7 and at least version 2.24 of anjuta.
* Reparse when a file is saved.
* Various bug fixes.

You can get it from here. I hope it'll be included in anjuta-extras for 2.26.

On other news, I've sent my gdb patch, you can follow the thread here(my latest mail is here).