You can add a Blu-ray player to that system, but you'll need to connect its HDMI video output direct to the TV, and you'll only get 'standard definition' surround sound, as the Sony system doesn't have HD audio input capability. Instead you can just run a digital connection from the new player's audio out to the Sony system.
Otherwise, there are various home cinema systems with built-in Blu-ray and either wireless rear speakers or the ability to accept a wireless rear add-on - as, for example, in Sony's range. Other new models with this capability are coming later in the year.
you probably know this but...
Wireless speakers still need to be powered so plugged into mains with ... wires. so it is not a completely wireless solution (rather a replacemetn of one wire with another) but if you have your power outlets located conveniently can save some wires between the amp and the rear speakers if this is the inconvenient part.
Yeah, I already have the 'wireless' rear speakers. I was just hoping to replace the DVD player with a Blu Ray and not have to buy a new speaker package.
Good to know I can just add a Blu Ray player, but I'm looking to substitute the existing DVD with a Blu Ray player and have it run the same set of speakers. Possible?
Yes, if you plug the Blu-ray player directly to the TV via HDMI and into the system using a digital audio link, you'll get the sound through your current speakers. You'll get the better picture quality of Blu-ray, just not the enhanced HD versions of Dolby Digital and DTS. But it'll sound as good as DVDs currently do through your system.