Pretty much nobody wants Ash to leave and there's a reasonable chance he'd be happy to stay so it would seem to be a fairly simple case of agreeing terms and everyone's happy.
In reality, things are far more complicated than that, Ash turns 30 at the start of next season so his next deal (whether a 2 year extension at the Swans or a 3 year deal elsewhere) will take him up to his 33rd birthday so this next deal will probably be the last 'big' one for him.
Below are some real back of a fag packet figures but show the kind of things he (and his agent) are likely to be thinking about.
Based on little other than speculation and guesswork, I'd imagine Ash is on somewhere around £40k a week and if he had 2+ years left on his contract it'd take offers of at least £10m+ for us to consider selling and I'd consider this his 'market value' if he was tied in to a long term contract.
I've seen rumours of Arsenal bidding £3m but at that price there's absolutely no financial point in selling (I'd understand the argument of letting him go for 'cheap' as a thank you for his service if he were looking to drop a couple of divisions to join his boyhood club or something, but not to join one of the richest clubs in the world).
There's also been the likes of Napoli mentioned where he could sign a pre-contract in January to start there in the 2015/16 season, for me this is an even bigger worry for Pablo than Ash as obviously it's far easier to imagine a situation where Pablo is happy to run his contract down and go back to Spain than it is for the upheaval of Ash moving to Italy.
The new TV deal that kicked in the season just gone meant than Swansea got £74.2m this season vs £47.6m in 2012/13 from Premier League money despite finishing lower in the league, so if income has gone up by 50% it wouldn't be surprising for players to want a rise that reflected this (or have already asked for it at the start of last season), although once you give one player a big rise it risks opening the floodgates and it's not just one player's wages you're increasing.
Even forgetting the lure of Champions League football, there is a serious amount of money at play: extend at Swansea on an improved deal and get around £7m+ over the next 3 years or run your contract down, and get a signing on fee and improved wages for following 2 years at a Champions League club (e.g., £2m Swans wages, £2m signing on fee then £3m p.a. wages giving £10m over next 3 years).
These figures are nothing but educated guesswork but I'd be surprised if Ash wouldn't be several million pounds better off over the course of the next 3 years by running his contract down.
I get the 'if he doesn't wan't to play for us, he can bugger off' argument but I can see why at the very least he's considering his options. Some may say Scott Sinclair faced a similar situation and took the money but I'd argue that in his situation it was a big leap to see himself as a regular first team starter at Man City although I'd imagine to succeed as a footballer you have to have a pretty strong belief in your own ability but I'd expect Ash to challenge for a first team place even if not a guaranteed starter .
Situations like these often descend into a game of bluff with accusation and counter accusation with a mixture of rumour, fact and speculation but from a negotiation point of view, every week that goes past strengthens Williams' hand. I hope I'm wrong but given the sums of money involved I don't see anything happening on this before August (if not January).