how bout just getting xbmc as a whole to run on the box
The Boxee Box can only do apps in a repository as far as I know. (In the software version it is sometimes possible to get XBMC add-ons / modifications to work but it's not all that common as Boxee has gone off in a different direction when it comes to add-ons/plug-ins/apps).
The XBMC Hulu add-on wouldn't do you any good because Hulu detects that you're trying to access from the Boxee Box and blocks you.
There are rumors of a Grooveshark app coming for the Boxee Box but in the meantime, it should be possible to use the Grooveshark website via the Boxee Browser.
Note: This is a users' community forum. For official support, submit a Support Request.
You can also find out how to Get Help or read the Boxee TV and Boxee Box Documentation.
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"Some people just aren't happy unless they're disappointed or angry."
Yes, running XBMC on the Boxee Box would be ideal, but it doesn't appear possible yet given the searching I've done. If apple TV can be hacked, I'm sure the Boxee Box can be too...
It is not possible to run XBMC addons within Boxee due to the vast amount of code changes done internally since Boxee was originally forked.
In Navi-X you can search Grooveshark and play tracks one at a time from those found and listed, but it's not much of a replacement for the real Grooveshark interface - which can of course be accessed from the Boxee Box browser without an app.