The timing of that means series 8 (or 8a if it's still split, though there's no reason for that ATM) would be starting at Easter 2014
It is very vague and interesting that the BBC could officially
announce 2014 series for a bunch of other shows this week but not DW.
I really do suspect now that they're waiting on Matt Smith to sign a contract for another full series (or not) before they decide exactly what they're going to do.
There's another possibility.
They may see no need to announce a 2014 series for Doctor Who
at this point when they still have a series to broadcast for 2013. Yes, the hardcore fan will want to know what's coming up a year from now, but the casual viewer would only be confused by announcements about Doctor Who
a year-plus out.