Beta on Tuesday, final on Friday … the Internet is great 🙂
This is mostly a service release that fixes some bugs, while also improving keyboard / accessibility cues for some dialogs. Get it via the built-in updater, or from the website: http://www.getpaint.net/
The change list is the same as it was for the 3.08 beta release
paint.net blog 
Hi,man, I am trying to use your paint to process experimental data.
Could you add a “fixed size” style into “rectangular selection”,like photoshop?
This is quite useful for me, if added, I think I could discard photoshop completely.