It's the Boxset of the 2008 - 2009 specials which were on instead of a full series that year.
I agree the box sets have been a total mess recently. I'm still hoping for a box set containing Day of the Doctor and Time of the Doctor because I'd rather buy them together and I really do not want to buy the other specials I already own, even if they are fairly cheap.

Is there a more ideal name for the set? 'The Complete 2009 Specials' would technically be inaccurate because the the last one was broadcast on the first day of 2010.

its actually 2008 to 2010! Christmas 2008, Easter 2009, November 2009, Christmas Day 2009 and New Years day 2010.
It would have to be called 'The 2008-2010 David Tennant Dr Who Specials' or something like that!

I always thought that they should have just named The Complete specials boxset The Fifth series boxset. Because, in a way it is.
Torchwood Children of Earth was 5 episodes, and everyone knows it's the third series, even though it wasn't a full series.
To me, If they labeled it as the fifth series instead of the complete specials, And Matt's series 5 would've been series 6 instead, that would have been fine to me.

I guess that would've been more ideal.