My wife has a craft business and is brilliant at almost everything she turns her hand to - her glass art, in particular, is spectacular (and always sells well). But she's a total butterfly - she gets half way to perfecting one great idea but then gets distracted by something even shinier and more exciting- and off she goes down some new path. I used to mock her for this (lovingly, of course - it has become a running joke between us) but now I'm getting that back in spades, as I'm mired in researching and drafting two very different novels - one set in Venice in 1576, the other in Warsaw in 1944, and whichever I happen to be looking at in the moment is definitely the more exciting...until it isn't!
I'm not sure this is a bad thing, and I think there may be real strengths to be derived from simultaneously working with different techniques and styles and ideas. However, I know sometime soon I'm going to have to commit to just the one, and increasingly (given recent experiences with agents and my last novel) I'm (slightly glumly) concluding that I should focus on Warsaw, because its way more marketable than Venice. At least that'll save me some of my wife's mockery!