I started noticing lag/connection issues around black friday weekend (November 23rd). Before that time my gameplay experience was great with no noticeable lag issues whatsoever. After that time every single game I play has bouts of severe lag that last for a few minutes. In addition, I will oftentimes be kicked back to the war games menu for no apparent reason. I've done the usual checks, my internet connection is fine, I've reset my system and uninstalled the game, but nothing helps. I don't know if a solution has been found for the issue yet, but at the very least I'll add my voice to those also experiencing connection problems.
EDIT: Oh, I should also mention that last night when I played I reached SR46, but today I was back down to SR45. Not sure what's up with that.
Oh, and here's some info for 343 if they're actually collecting any:
A) Gamer Tag - IridiumDragon
Location - Portland, Oregon, USA
C) Last time played? - 8:15pm PST
D) Were you using Mtn Dew XP? - No
E) What rank are you? - SR45 (should be SR46)
F) Were you in a match or Idle? - War Games matchmaking game.
G) Can you connect to anyone else? (been reports that some have connected back randomly.) - Yes.
H) Have you tried cleaning your Cache or doing other things to try to solve the problem? - Reloaded content, re-booted modem and router, and re-loaded gamertag.