My Web host is busily upgrading the Debian Linux machines on which my sites run to the Lenny release.
Of course, I had to find out: why “Lenny”? Turns out that Debian releases are named for characters from Toy Story. (The next stable release is dubbed “Squeeze.”)
Whether this will affect uptime, I do not know, but I suspect the impact will be small unless I’ve still got some stuff floating around that runs on PHP 4, which dates back to the Ice Age.