I was trying to keep it spoiler free, Pete
Some might not want to know anything about it until it airs.
Also, they've only changed it a lot recently. The titles stayed practically identical throughout the 2005-2010 run, and they only changed the theme tune once.
They changed for Matt Smith's introduction in 2010, and then they decided to do the whole "blockbuster" themed titles for the five episode of Series 7A. Then for Series 7B they introduced another version.