As discussed in an earlier post, Trump can only win the Republican nomination if he improves his perceived electability and convinces voters that he is a genuine conservative. The "birther" issue does not help Trump in either of those areas.
When Obama released his birth certificate, it provided Trump a good reason to move on to other matters. Indeed, Trump's first act was to call a press conference and declare victory. That's not to say there will be no fallout: Trump had insisted he hired private investigators, and that he heard the birth certificate was missing.
Trump's calls for Obama's education records may be met with more skepticism from the press now that Obama has at least released something, even if it was unrelated to the new demands. In addition, some may attempt to drag Trump back into the controversy if "birthers" question the authenticity of the birth certificate.
Nevertheless, Trump was given a much-needed escape hatch. He has the opportunity to engage on other issues, ones which may help him improve his perceived electability and perceived conservatism. Whether Trump takes the opportunity, and whether he is successful, are other matters entirely. Elephant Watcher still calculates that Trump has a 1% chance of winning the Republican nomination.