343 Industries' Frank O'Connor, Josh Holmes, Kiki Wolfkill and David Ellis all got together for a Halo 4 podcast to share some information on the upcoming Xbox 360 exclusive. While the group spent the majority of the time talking about the recently revealed multiplayer maps, they did drop some nuggets of weapon information toward the end.
The DMR from Halo: Reach will return with Halo 4. It served as a replacement for the Battle Rifle but was not as well loved by fans of the series. How the two will fit together in the same game is unknown but 343 says they will both have their uses. For example, it is easier to shoot down mid-air enemies with the DMR according.
Originally introduced in Halo 3, the Bubble Shield will be absent from Halo 4. No reason was given for its absence.
Finally, the Assault Rifle received a mention as well where it was described as "beefy" and "sounds amazing". Players will still need to burst fire with it to be effective but so far it sounds like its power has been improved upon from previous titles.
You can check out the entire Halo 4 podcast at halo.xbox.com.