Talking about a federal UK is silly. There is no public desire for this, especially in England.
People in England generally don't want another set of politicians in their lives, especially politicians with poorly defined powers (see also: why we are not a republic and have no elections for Lords). It works in Scotland and Wales, because they're small and have specific local issues to manage. Scotland has the huge advantage of already having a separate legal system.
However, England is far too huge and diverse to be a state in a federal system. You can't have a federal system where one state is 10x the GVA of all the others.
To give each federated state roughly equal power, you'd need something like 9 English regional states Even without London, the rest of England is still 8x more GVA than scotland
(
this wiki gives a good breakdown)
And what happened when we asked the North East (similar economic size to Wales and about as culturally non-London English as you can get) if they wanted devolution?
Nope
The May/Sturgeon talks are very interesting though. It does make me think May is trying to kick this stuff into the longest pampus grass she can find. She is totally opposed to Scottish independence, as are most Tories (and probably most English people), so it probably benefits them both is Scotland blocks/delays Brexit. May gets more time to think, Sturgeon takes the 'blame' while also standing up for Scotland.
Sturgeon probably knows that indieref2 would be close, and might prefer the long game, rather than a hard Brexit, snap unilateral indieref, massive political fight and economic apocalypse (full Brexit + indieScotland negotiating re-entry EU = utter short-term disaster for the Scottish economy and loss of a lot of independence support). If Sturgeon can get credit for securing a better deal for Scotland, then it goes down as yet another reason why the Scottish need more decision making power in Hollyrood.
Oh, and that poll of opinions on May/Corbyn... How does May only get 16% "nasty", especially when Corbyn gets 18%? The rest of the figures seemed as I expected, but I've always thought of May as the stereotypical "nasty Tory".