Apparently, Epic Games V.P. Marc Rein did an interview with Game Informer recently where he talked about his team still working on current Gears of War content. After putting out the expanded maps and updates recently, Rein had this to say regarding Epic's current work:
"You saw that we put one update out, and we've got another one coming out any day now - I'm not exactly sure when, We have another update in the works with a little surprise in it, and we have more downloadable content. We're still working on making Gears a better game. You'll have to wait and see what comes from that."
Looks like Gears will continue to stay ahead of the pack on the Xbox 360 for a while longer.