Is there a master deck list of on-going exofacto standard decks?
In particular, ones being played through the PTs?

Not that I've seen on this site. I usually have to check many sources to figure it out and even then I have to account for my local meta game.

edit: Tournament reports are a great source of up-to-the-moment decklists.

Lovely, was hoping for an end-all-be-all information source :P

Oh well.

Thinking of getting heavy back into standard, and maybe shoot for a PT given the prize purse is nice these days, and it seems much more accessible.

Unfortunately my local shop currently only does drafts for FNM so I don't get to see a lot of what is being played regularly.

I think that between the myriad of strategies and variations among those strategies it would be near impossible to keep a proper list. How about this to get you started:

In no particular order, and only by the names I know them as, here are some popular decks at the moment.

Pod (Naya, Mono Green, BG, BUG)
Tokens (BW, GW, RG)
Control (UB, UW, Esper)
Heartless Summoning (UB, BG)
RDW
Tempered Steel
Spirits (UW, Esper)
Wolf Run (RG, Naya)
RG Beats

I am sure there are many more and some of these may even be outdated already (e.g. Tempered Steel).

Thanks! I shall have to dig through my collection and try some of these out.

There's also Delver. Used to be u/r, now it is generally u/w with invisible stalked and geist or saint traft. Zombies is also very much a deck, playing geralf's messengers and phyrexian obliterators. I've seen humans as well, largely because champion of the parish allows for disgustingly aggressive starts. Slightly more fringe are grand architect builds, unburial rites/frites, vampires, and monoblue runechanter pike aggro. I could go on!

Much to think about, I am teetering on the idea of a U/? deck of some sort as control is always pretty key.

If you go on tcgplayer someone wrote a good article about the top teir decks and posted deck lists of the more common varieties. They also have deck lists from top 8's of ptq's and mtgo.