Rumors tonight suggest that Etihad is likely to become the latest corporate sponsor of MLS. That is the league as a whole not just NYCFC as some have suggested. Remember in the UK there are not as many international airports (Manchester and London by far the biggest) so its not really a comparable situation. I would guess it could be another Abu Dhabi startup (Etihad is still relatively young and ran at a loss until recently) but you never know.
Are the club likely to bring out a jersey without a a sponsor. Maybe as a limited edition? Some people have even suggested doing the first season without a sponsor presumably for shirt prestige reasons.