Depends how far you are from the router. Most likely not if you are not to far. 54 Mbps is way faster than your internet connection is capable of carrying. If you have cable, anywhere from 3Mbps to 10 Mbps, and DSL is lower.
That would slow down a LAN connection, but not significantly to be noticable. I think you'll be ok bud, but in all honesty, give each a try. I had some problems with my 360's wireless adaptor (Linksys made) connecting to the Netgear router we had. It would attempt to connect to itself, strangely enough.