I agree with you Gaz, it does look promising. Also, I just checked on my N800, when I check the profiles it supports with my phone, HFP is there. It looks like it just requires the right software.

This reminds me of when I used a Samsung T10 for a short while. You can tether that to your phone through bluetooth, and it pauses your music when you have a call, and you can use it's built-in mic to use the thing itself as a phone! I found it pretty nifty. If that can do it, the tablet certainly can. Has anyone else used a T10 and knows what I'm on about?