I have put in place a new way to download code blocks from nodes. You should see a small link to the bottom-right of code blocks which if followed will display in raw the content. If this annoys you, please visit Node Display Settings and disable it there. Likewise there you can configure it to show the link only when the code is over a certain number of lines. Obviously I've defaulted it to on, as I figured most folks would like it. Also you can use the css class 'embed-code-dl' to change the way it is styled.
A note regarding setting the minimum length. The above is 4 lines long (even though it may not look like it) and comes from markup like the below:
Some users with custom CSS that uses the specifier .code for styling tricks may find these recent changes lead to ugly results. That would be because the structure of the code output is more complex with several tags with .code applied to them. The solution is to change the .code to pre.code,p.code and things should work out ok. Please continue to report issues.
How this is dealt with with probably be a little unstable for a few days until we can come up with something that looks good for everyone. Sorry about any annoyance this had caused.
Updated to reflect feedback and code changes.