It is portable, Orb works over 3G. The reason you might read otherwise is that 1) it started off wifi-only before adding 3G and 2) about a little over a week ago there were some AT&T related connection problems that have since been resolved.
I'm using it as a stopgap until Slingplayer gets released. Unfortunately it's Windows only for live TV at the moment, there's a Mac version in development (can be downloaded from their support forum) that doesn't support the function yet. You also will probably need a usb-irt blaster (another $50) to change channels, the Hauppage won't do it on its own. You also need to keep your computer on when out. It can supposedly record shows to your hard drive, but the one time I tried I didn't end up having enough space on my Windows bootcamp partition.
My experience overall - a PITA to set up but extremely cool when it's finally working. At this point though with just two months left till submission I'd probably advise you to just wait it out and use the money you save for a Slingbox (which will give you DVR access).
The Orb app itself is definitely worth downloading btw, it can play files from video formats NOT supported on the iPhone like .avi.
