The problem is that this would be one of the most widely used PHP extensions being deprecated, so they're just being careful. This is not the normal way things are deprecated, but education is a good way to start the process of removing popular functionality from such a popular programming language.
Exactly. For something like ereg, it was a lot easier to just deprecate it and go from there. For mysql, it's such a commonly used extension that a softly, softly approach is needed, no matter how much it would be nice to get rid of it immediately.
If they do actually add E_DEPRECATED to mysql/ext they will probably have a really hard time every depreciating anything ever again.
mysql/ext is so popular that all default installations will start hiding E_DEPRECATED, which means that no one will ever again see depreciated warning even for things that are easy to fix.
Deprecation is a signal that it will be removed in the future, not an immediate removal. The entire point of deprecation is that it allows library authors to signal that a thing will be removed in the future, down the road, when everybody as switched to something better. If that mechanism isn't reliable, then apparently there is something wrong with the language community.
