Windows Phone 7 could have the slickest API, the best hardware, the largest numbers of users, and the most developer and customer-friendly application market and I would still resist making apps for them. This is a company that has a long and storied history of sitting on their ass and doing nothing to push the state of the art, once they've captured market share. Their mobile strategy over the past decade is itself a good example of this. And it isn't like there has been some big culture shift over there that might put the lie to this, either. In fact it seems to be getting worse.
(Although, in fact, if they were to pull off all of the above without e.g. first buying Samsung or some bullshit, my opinion of their capabilities and culture might need some reworking at that point.)
Unless you're really exciting by the prospect of developing for Windows Phone 7 for the next fifteen years, you should be glad MS barely qualifies as an also-ran in the smartphone game, and hope that never changes.
(Although, in fact, if they were to pull off all of the above without e.g. first buying Samsung or some bullshit, my opinion of their capabilities and culture might need some reworking at that point.)
Unless you're really exciting by the prospect of developing for Windows Phone 7 for the next fifteen years, you should be glad MS barely qualifies as an also-ran in the smartphone game, and hope that never changes.