Not a dumb question - I asked the same thing when I first joined the forum when 2009 came out (hang on, maybe it IS dumb then

Being a rolling release I believe the repo folder path (2007) was kept for simplicity.
I haven't seen any announcements but I do know that the repo's now have a 2010 folder in them so the Synaptic path may change sometime in the near future (I would imagine the
sources.list file will change automatically to reflect any change that may/does occur)