You didn't say how fast your Internet service is. There's an increasing spread in the available Internet speeds, and of course if you're on an entry-level "lite" service, most routers will be able to handle the speed without bottlenecking, but if you're on a very high end service, many consumer routers will not. That said, most people fall somewhere in the middle, and most modern routers can handle that just fine.
Another thing to consider is that, based on the lifetime of your last router, the next router may last a long time, and into the next couple of bumps in Internet speed in your area,
perhaps.
See SmallNetBuilder for their router charts and reviews. Their reviews tend to focus on wireless issues, but also have some WAN-LAN and maximum connections measurements which are useful.
http://www.smallnetbuilder.com/component/option,com_chart