After a few months of wrangling, the NFL and NFLPA have agreed to the previously proposed changes to the injured reserve rules.
The trade deadline has been moved from week 6 to the Tuesday after week 8. The issue with it being in week 6 is that most teams still think they have a shot at that point. Allowing trading until after the week 8 games will give teams a much clearer picture of where they are and could lead to increased dealing.
The IR rule is a little more convoluted. One player who has a "major injury" and is placed on IR after September 4th, just prior to the start of the season, can now be brought back later in the season. This could affect a player such as Mike Patterson or even Jason Peters. Both players have already been placed on non-football injury lists, so I'm not sure what their availability for this rule would be.
To utilize this rule, a team would have to carry an injured player on their 53 man roster after cut down day and then put him on IR after the season starts. Any player hurt in season can go IR and be brought back later. But again, this can only be done once in a season.