It was dicussed in a thread a few months back about the remastered boxsets in this forum.
Over here in the UK they released the first season of ST:TOS on DVD with the HD-DVD one side & DVD the other,then season 2 & 3 never materialised.
Turns out they have repackaged them & are releasing them like this :
So if like me you bought the first boxset you now can't complete your collection of matching boxsets!
They are also re-releasing the original movies in a 6 box set & all the TOS boxes in Blu-Ray as well. All in time for the new movie it seems.