Well that was a short beta test period, wasn't it? Like I said this isn't really a 'major' release like 2.5 or 2.6 were, it's more of a .01 release along with some bundled effects that have already been available for awhile. And it also accomplishes moving all the Paint.NET clients out there to start pinging the new website domain for updates (instead of the old hosting that was on .edu). So a .01 version bump just wasn't enough. There was also 1 little bug fixed, it was one of the more annoying ones though.
Anyway get it via the updater (File -> Updates -> Check Now), or from the website, http://www.getpaint.net
New stuff in this release:
* New effect: Glow
* New effect: Bulge
* New effect: Polar Inversion
* New effect: Tile Reflection
* New effect: Twist