Features being added in the upcoming 1.5.0 patch

[Cairenn]

Changes to the UI in the next content patch (1.5.0), as posted by Slouken in the Blizz UI forum:

Party Pet Info:

In the next big content patch (1.5.0), you will be able to use these new unit names:
partypet1-4
raid1-40
raidpet1-40

When these units are in your area of interest, you will be able to get full information on them. When they are not in your area of interest, you will be able to get as much information as you would on party members which are far away.

This has been implemented in an extremely bandwidth efficient way, so please switch to using them for all raid information mods.

Sticky thread on Blizz forum.

UnitName("player"):

In the next big content patch (1.5.0), UnitName("player") will always return the correct name of the player character. You will no longer have to wait for name update events (although they will still occur).

Sticky thread on Blizz forum.

Signed GlueXML files:

There had been a stickied thread, which has been removed, but the gist of it is that you will no longer be able to edit the files in the GlueXML folder. They never intended that folder to be touched, and they are going to be enforcing it now. Any mod authors that have made changes to files in that folder (ala Auto-SignIn type addons) need to get rid of them.

While the original sticky thread is gone, there is still this one.