There are more hints that Alonso would like to move on to pastures new.
http://www.grandprix.com/ns/ns28087.html
In the short term as in 2015/16 I can only see 2 teams capable of winning championships namely Mercedes and Red Bull.
McLaren might be able in '16 but I suspect it might take another year or two depending on how could the Honda motors are and getting their technical problems sorted.
Ferrari I suspect could take longer to be championship material.
That leaves Alonso with 2 teams who both currently have strong driver lineups that will need to be changed. I am not sure of the drivers contractual situations as to who is out of contract at RB and MB at the end of this year.