2016-04-12 Update: Removed link to UI My current UI does not display XP which prevents the masochistic nature of checking XP til-next-level instead of actually leveling. So, a friend threw out the following macro.

/script ChatFrame1:AddMessage(string.format("XP to next level: %d",(UnitXPMax("Player")-UnitXP("Player"))))

He also threw out a neat speed macro which reports your character’s current travel speed.

/script ChatFrame1:AddMessage(string.format("Player Speed: %d%%",(GetUnitSpeed("Player")/7)*100))

Both macros are single lines, so make sure when entering them that the line is not split.

User comment by Drey:

[…] the character pane, as of 4.0.6, now shows you what your maximum speed in your current form / on your current mount ought to be. The macro is still useful for seeing what speed you actually *have* however; before patch 4.0.6, druids weren’t getting the correct speed modifiers in flight form.