Continuing the effort to make all the classic series soundtracks legally available for digital download, Capcom has added the Mega Man 2 OST to the Capcom Store. For $8.95 you're not just getting the original NES tunes, but the entire Complete Works tracks, too. The entire soundtrack in DRM-free MP3 format, exclusive to North America and South America.
Stay tuned for the Mega Man 3 OST. The soundtrack should be up for grabs sometime this week.
Source: Capcom Unity (thanks for the tip, Jon)