Greetings!  I've owned an IQ507 for a little over a month now, and it's a fantastic machine.  I found this site early in the process of setting it up, and I've it found it very helpful. 

I have done quite of bit of tinkering with the Vista Media Center (VMC) functionality that is built in.  It has been frustrating at times, but I'm finally at a place where I'm pretty happy with it. I thought I would share some of my experience that others might find value in... (even if it is a run-on, stream of conciousness novella (sorry!))

My original plan was that I would be able take my cable set top box from my 'man cave,' and move it to the kitchen (where my IQ507 is located).  I would hide the cable box in a cabinet, and run the HDMI cable from the cable box to the computer, and an IR blaster from the computer back to the cable box and (viola!) I would be able to watch all my cable programming on the computer, and I could 'extend' all that functionality back to the 'man cave' using an xbox360 there and it's build in capabilites to act as a Media Center extender.  I had a wireless N network in place and expected to use that for connectivity.  That plan was epic fail, LOL.  There is no HDMI input on the IQ series machines (Looking back, I don't think it would have worked that way even with an HDMI input)

Further research let me to believe that what I needed was a 'place shifting' appliance to get my cable programming on my IQ.  There are a lot of options out there.  Slingbox is the leader.  I ended up getting a HAVA device, which is a lot cheaper.  It does work as advertised - the functionality is there, but I was disappointed with the picture quality.  Others on this board seem to be happy with the Slingbox Pro HD... (I don't know)

The other issue that quickly became apparent is that wireless (even N) kind of sucks for streaming media.  I added ethernet drops so that I could get my computer and xbox connected to each other and the Internet on a gigabit switch.  Btw, this turned out to be a lot easier than it sounds -- I used existing condiuts for phone and or cable in my house and added new faceplates with the RJ45 ports.  That helped a lot, but the picture quality still was not that great.

Then I had the epiphany.  Just to see what it would look like, I went to Radio Shack and bought a $28 indoor TV antenna (rabbit ears), and connected it to the TV tuner on the IQ507 (it's the coax input).  Wow!  Crystal clear, smooth as silk HD for free.  I live in an urban area and the signals all the networks are strong.  I hadn't watched over the air TV in 20 years and hadn't really even considered it to that point, but it's awesome.  The quality and performance are equally good extended to the xbox on a 32" LCD TV.  The HAVA device went on ebay immediately.

I've since added a piece of software ($40 (2 week free trial) called PlayOn (http://www.themediamall.com/playon) and it's VMC plug called VMCPlayIT (http://myweb.cableone.net/eluttmann04/projects/vmcPlayIt/default.html) to get Hulu (www.hulu.com) content in Media Center.  If you haven't heard of Hulu, it's a great site that provides tons of cable TV shows for free (legally) over the Internet.

I also set up Netflix account which I would recommend as a great service that can also be accessed through Vista Media Center.

The old cable box has been returned to the cable company which saves some money, and I really have no regrets so far.

It's been a long strange trip.  I like to tinker so this kind of stuff is entertainment for me.  I know a lot people find this stuff down right aggrevating.  So, if you are considering using your IQ for TV and you don't really want to fuss with it to much my advice is:

1. If you are going to stream multimedia or extend VMC, using wired (as opposed to wireless) connections is going to be a lot easier.
2. Give 'Over the Air' TV a chance - it's easy and cheap to set up and the picture quality can't be beat.
3. Hulu and Netflix are inexpensive (free and $9/month respectively) sources of good content.

I'm fairly new to the multimedia world.  I'm sure there is a lot more to learn.  I'd love to hear what's worked well for you with your IQ.  Thanks for reading :)