This means one of two things: Pelosi already had the votes without Stupak and he got a small "concession" that he knows is worthless but hopes, on some level, that it will help the pro-life cause. On the other hand, it might mean that Pelosi was in such a tight spot - she needed Stupak but couldn't push through a second vote on the abortion question - that this was her only option. And it "worked" in the sense of it got the Stupak bloc on her side.
Time will tell if the executive order "works" in limiting abortion funding or if it's exactly as it seems to conservatives: a flimsy excuse that no pro-lifer in their right mind would accept.
President Obama is ardently pro-abortion. How long will his "resolve" to stick to his executive order last?