I'm not running anything like what you're describing in my home (or my office for that matter -- lord, I'd never get *anything* done), but I think I might be able to answer your question.
The DLink, Linksys and MS boxes are all designed around a single console system. They are wireless adapters -- think of them like wall-jacks and you have the right idea.
Regardless of any adapters one may be using, at the end of the day, the Ethernet jack in the back of your console is still just that: an Ethernet jack. I'll bet if you pick up a Wireless Router with the five-port "wired" jacks in the back, you'll be able to hook all your systems up to the wireless network.
To configure this, what you NEED to do, though, is configure that second (I'm assuming it's the second one, that you have another wireless router somewhere else in the house) wireless router to NOT be a router. All you want it to be is an access point.
You can just go and pick up a wireless access point but you need to make sure that has the Ethernet ports on the back or else you're back to square one.
Think of it this way:
---plugs in to----
Wireless Router/Hub/Switch #1
----which sends a signal to----
Wireless Router/Hub/Switch #2
----which is connected, via cables, to----
Your X-Box, PS2, GC, etc.'s Ethernet port. You are now wireless, which is to say your consoles are connected without having a seperate adapter for each and every one of them.
There is absolutely no reason I can come up with why this wouldn't work. Enjoy!