My Suggestions For A 6K Setup
How about this:
If someone gave you 6 grand to put together a dream system for yourself and you already had a killer television and disc player, what would you pick? Room is 15' by 20'. Cables and stands are already taken care of.

I plan to get either an all-in-one player that does SACD/DVD-A and Blu-ray or 2 separate players that handle both. Components should be able to handle HDMI 1.3a as well. No need for XM radio. iPod connectivity would rock. (I think just about every receiver does this now, though.)
Ok Lucerninblue....I am going to run with this hypotheical 6 grand and you will have one sweet set-up in the end...I will list the component possiblities with prices and then what I would pick for 6 grand...I am going to go on the assumption of a 5.1 channel setup...
AVRs:
Denon 3808ci -- $1099, I think you still might be able to get this special price that was once offered to forum members (J&R matched it for me)....I did and another user even got his local Magnolia at Best Buy to match this price which is a pretty sweet deal...
Onkyo TX-NR905/906 -- $999 - $1,245...This is Onkyo's top end AVR and these prices can from Authorized dealers on Ebay....you can get the 905 (older version) for $999 refurbished or you can get a NEW 906 for $1,245...these are all very good deals and this receiver has ALOT of power and top-end video processing...
Amplifiers (optional --- but your budget could possibly accomodate it)
Emotiva XPA-5 -- $799 -- 200 watts by 5 channels --- not sure on this one some love it and some have had issue with reliability...
Sunfire TGA-5200 -- $1,600 -- VERY good deal on a new 5200...a authorized dealer has been selling them at this price for a good little while on E-bay...
Their are others but prices will vary whether you go new or look for a deal but these two are solid for sure....You could also look to B & K, Parasound, Theta ---but with these you start to talk serious coin $$$
Speakers:
Here is were things get a little icky as speakers are so much a personal decision....but I will try to give you ones that have garned high grades universally....
SVS -- MTS-01 line -- These have got nothing but glowing marks and would be what I would go with bar none...SVS in terms of performance in what you pay for is astounding....
You can also check AV123 another internet direct company and Paradigm as well as Dynaudio...with the later two you start to talk more money again...
Subwoofer:
For your set-up I will suggest simply two:
SVS PB13-Ultra -- $1,599 (Seems to be the king around here -- ported)
HSU ULS-15 -- $1,399 (Another killer that is a sealed unit)
Players:
I would go with these two:
Blu-Ray: Panasonic BD35 -- $299
Universal DVD/CD Player: Oppo DV-983H -- $399
So with all of these choices this is what I would go with...
Denon 3808ci -- $1,099
SVS MTS-01 Full Size 5.0 System -- $2,699
SVS PB13-Ultra -- $1,599
Panasonic BD35 -- $299
Oppo 983H -- $399
Total: $6,095....
And you will have a KILLER system...now if you want more power go with the Onkyo over the Denon (the SVS speakers are rated at a 84db sensitivity which ok, but they are 8ohm so don't present a huge load to the AVR) and you could save some money by going with the Oppo 981 which would put you right at 6k....Sorry this post got really long but hope that it gives you some ideas and routes to persue...