Yes, Kroy Biermann has returned. Contract terms are not immediately available.
This is likely to be a relatively low-cost deal, given the lack of reported interest for Biermann on the open market. It's also likely to be one of the most controversial moves of the offseason, given that the nearly full-time starter snaps Biermann received the last two years caused a dislike in the fanbase that could charitably be called palpable.
Dan Quinn's likely to utilize Biermann primarily as a reserve defensive end or part-time starter, though he could move around the formation a bit as needed. You're unlikely to see the 65-80% of snaps he's gotten in recent years, and chances are his per snap effectiveness will be better for it. If he's getting the contract I suspect he is, and you take out his tumultuous history with the fanbase, it's a fine signing.
Of course, given the fact that the Falcons are sitting on quite a bit of cap space and have only made some low-cost fixes to the pass rush this far, I can't and won't expect fans to react to this like it's any other signing. Biermann's going to have to prove his worth and then some under Dan Quinn, and Quinn's going to need to find a way to ensure Biermann's much more successful to return the fanbase's appreciation of him to pre-2013 levels. If he's able to play part-time, deliver a handful of sacks and play pretty effective run defense, chances are he'll be worth the contract.
Welcome back, Kroy Biermann.