"receiver can handle HDTV and Blue-Ray "
I looked up your Denon - it has this listed:
"Front, 1 x 5.1 channel audio line-in ( RCA phono x 6 ) "
If you buy a player that incudes the decoding you are looking for, it seems like you can use your current receiver to accept the decoded signal by your player and pass on the information to the speakers. This will allow you to get all of the latest processing mode that is available in your player.
As far as HDTV - what setup are you using? Most of the new audio modes are currently not available on your HDTV offerings (cable or satellite)...
Here is where I found the spec's for your receiver:
Denon AVR-2802 Specs. AV receivers Specifications.
It has the following decoders listed as being available by your receiver:
DTS Neo:6, DTS decoder, Dolby Digital, DTS-ES decoder, DTS-ES Matrix 6.1, Dolby Pro Logic II, Dolby Digital Surround EX
I have a DirectTV HDTV decoder - and most of the signals are in the Dolby Digital domain - so your receiver would handle that as well.
If you want HDMI switching, or on receiver decoding of the latest sound processes - then you should look into getting a new receiver.
You can also just use your current one, get your Blue Ray and HD-TV receiver, and live with the players decoding until you find something in your price range. I wouldn't let an older receiver stop me from getting into the HD game...