I have this system - how should I upgrade?

[CptGreedle]

http://www.sonystyle.com/webapp/wcs/...52921665093459

This is the info on that model.
It does support HDMI, but only 720p/1080i. For FULL HD, you need an AV receiver that supports 1080p. In addition, it looks like it is only a 5.1, and adding more speakers will not be possible. Not everyone needs more speakers, but if you ever wanted to...
Also, this is a lower end model. If you really want a good model, get an Onkyo receiver. I use Yamaha as well, and have no complaints. These speakers should be fine, but you will want to upgrade them eventually, over time.
A really good system does not come in one box, but are separate components. So do as I did, start with that, and upgrade slowly... starting with the receiver. I still need to get a better Subwoofer, but I already have upgraded 4 of my speakers and am looking into more.