Sorry, one last point I forget to mention above. Several vendors offer a wireless-to-ethernet bridge device. Linksys, for example, has the WET11 and WET54 product, and other vendors offer the equivalent (sometimes labelled as Game Adapters for X-Box appliances).
In any case, these serve a useful role in allowing you to take an AP from one Vendor, and with the wireless-to-ethernet bridging device, create a point-to-point wireless bridge with normally incompatible equipment.