If you have no interest in Halo 4, sell now and don't look back. Sell PS3 as well, get as much ammo you can for the WU, if money is the issue.
I sold my PS3, but kept the 360 for Madden (the last one, its Wii U vers. next yr) & Halo 4.
No shame in my game, even as a Nintendo fan, I sold my GC and like 20+ games, paying off a big chunk of OG 360. The only console I didn't sell was the SNES, but got pissed one day and smashed it in my garage (R.I.P).