The long and the short of it? Nathan Dyer's only at Leicester because his wife was banging Swansea City FC's richest director behind his back, management (Monk and Co.) didn't back him up when he found out as they were more worried about keeping their own jobs, and so he got carted off to any club that could be found (in this case, Leicester) never to be seen again. It caused heavy unrest in our squad as Dyer was a stalwart, players stopped playing for Monk as he didn't back up Dyer throughout it all, the club nose-dived down the table, the old guard like Britton and Routledge were being singled out and left to rot by Monk, but Monk thankfully got fired in the end and we've got a sense of control again at last. The issue is that we still have that bloody director on our board, and he's our richest one so there's not really anything we can do about it.
So when we have to put up with pundits and fans forums saying "I can't believe Swansea sacked Monk, what a stupid move, blah blah blah", it's not purely footballing reasons as to why he ended up leaving. Part football, part politics, part Nathan Dyer's missus affair.
To answer the actual question... He has 1 more year on his contract. Ends in June 2016.