The Eagles are reportedly willing to release Jackson if he can't be traded. Unless some team is willing to break the bank for Jackson (which is suspect since the Eagles are willing to dump him) he might have to take a one year deal to reprove himself to the league.
If Jackson came to New England for a one year deal with tons of incentives, he could easily have a 1,400 yard 15 TD season, especially playing with a great QB for the first time in his career. If he showed big numbers and a winning attitude, he'd rehit the market next season at 28 (still in the prime of his career) and could land a massive contract for a team needing a number one WR. Plus it's also a WR talented draft, which may also prevent other teams from breaking the bank this late in FA on Jackson.