ATF can't do crap about a domestically produced .223 semiauto rifle, whether they like it or not. Lots of ARs, Mini14s, AKs, etc, built and sold every day.
I think some rumors are more likely to hold water than others.
The XCR will be here one day. Sure, it is almost a year late now, but considering they don't have a single government contract on the table to my knowledge, the only way they are going to recover their R&D costs is through civilian sales.
I won't believe a civilian Sig 550 till I see it. Doubt Sig has any interest in producing rifles here, and don't know of any time where they have demonstrated such interest.
HK? They did sell the HK-91 and derivatives here. More recently, the SL8 *during* the awb. Civ G36 doesn't sound totally out of the realm of possibility, but still unlikely.
FN? They continue to sell the Five Seven despite the backlash. There are undeniable, confirmed, real deal statements that they intend to sell a P90 and F2000. I don't find it difficult to believe that they wish to sell a SCAR. Just the fact that it is "SOCOM's rifle!!!!" would drive sales through the roof.
I believe my next rifle is going to be of the new generation. Preferable choice for me would be a SCAR, with an XCR a close second. Maybe one of each. If the SCAR never materializes, make mine an XCR, 16", 5.56, full ambi controls.