Except that it's not.
Except that it is. "/day" or "per day" is only used in charts where they have to squeeze a lot of data into a very small space. The descriptions of the mechanics all refer to long rests.
Except that it's not.
I only have the issue with short rest type abilities when there are multiple abilities for each class and when you use up one ability, you still have access to different one. As long as it is a single power or multiple powers attached to a single resource, I have no issue.
That said, Wild Shape at basically At Will would be kind of game breaking for a lot of games as the Druid can shape into animals that can easily by pass encounters. Rage as it is right now, I think it would be overpowered.
How does wild shape allow one to bypass encounters? Even if a druid could use an animal form to sneak past something, swim through something, or fly over something, he can't take the rest of his party with him.