I am still hoping that Apple will later come up with a Gig-E version for some extra money. I think one of the rumors was about X2 / X4 Airport Express. Perhaps there is a X4 version coming up later. The way it is I wouldn't buy it. I have passed on buying any 100Mbit network storage, why would I shell $179 for a network storage solution that only provides 100Mbit connectivity to the network. It would seem like enough bandwidth, but I am pretty sure one will think differently when trying to move large video files across. Other than that, it doesn't make sense to me to have the wireless capacity so much bigger than the wire capacity.
Furthermore, pretty much all current Macs, or all of them (I haven't done the research) have Gigabit Ethernet ports, it would be nice to have a switch that can let them talk to each other at that speed. Before the age of video 100Mbit was good enough, even for most broadband Internet a 10Mbit would still be fine, barely, but with video 1Gigabit is about what's needed.
I am myself not in a rush, so I'll wait to see if Apple comes up with a Gig-E version of the base station, or if I get tired of waiting and decide to make the jump I'll consider Linksys or Netgear. However, before doing this I'd like to be sure I can update the software in my Mac to enable the draft-n capability and that this is compatible with Linksys/Netgear. I hope the enabler software becomes public after a while, it would be pretty lame for Apple to tie it completely to buying the base station. It could also be that the draft-n cards present in the latest Macs are not compatible with Linksys/Netgear, but I'd really doubt it.
Summing up. We'll have to wait a month or two for things to settle and know what can be done with our Macs when it comes to draft-n.
PS: If you don't plan to keep a separate g and n networks or do not have all the devices able to do wireless n then the performance will suffer when a wireless g device joins your network. This has been pointed in several other posts.