Hopefully my PC specs are in my signature if not and you want to know just ask.
I have cable internet up to 30MB/s speed. Currently using a Netgear N150 WNR1000 router. Connected through ethernet is two Xbox 360s, and my PC. Wireless we have a Sony Media player for Netflix and Hulu, and two iPod Touch. Soon we will be adding a Tablet prob Transformer Prime. One of the TVs is a 1080P HD, so i stream in HD on Netflix and others. I also have TVersity on my PC to stream downloaded movies to the 360s and media player. I play MMOs on the PC and online games on the 360. I am going to upgrade my router as mine is just crap now. I just want to know if its worth it to get a gigabit ethernet router. Most of my time i play MMOs and during that time two different tvs couldnt be streaming movies off my PC at the same time. So i dont know if my router can handle that now or not. Any advice would be helpful.
Gigabit is great if you are doing a significant number of wired Ethernet transfers between gigabit capable devices. It greatly reduces transfer times. If everything is working well now, I would try to get by until next year when faster wireless solutions will be coming. If not, then update now.