As far as I can tell, nobody has done this in some time. I don't know why, considering how many Premiership teams there are in Britain's capital city and how often they play each other each season. The premise is simple: a single table that calculates these teams' record against each other in all competitions (this would obviously lead to an unequal amount of games' played as some of these teams face each other outside of the league. But we can worry about that later). As might be expected, the London table mimics (but does not carbon copy) the teams' standings in the EPL:
As you can see, Arse has not lost any of the London derbies they have played this year. In fact, until the Jan. 9 League Cup match against Spurs, Arsenal had not dropped any points in these games. Their inter-London goal difference is pretty impressive as well (as a side note, Spurs have scored three of the goals against them, the fourth coming from Fulham's David Healy in the season's first minute). I also found it interesting that Spurs are better placed in this table (ahead of Hammers) than they are in EPL, despite having played Arsenal three times already.
Unless some of these teams are drawn together in league, FA or European cups, it appears Arse will run away with the title. Arsene Wenger's men only have three London derbies left on the schedule: Fulham Saturday, Spurs Tuesday (return leg of the League Cup) and a visit to Stamford Bridge March 22.