Early reports in the Russian media report that Phobos-Grunt has come down over the southern Pacific Ocean at 17:45 UT (15 Jan).
These same Russian media have misinterpreted decay bulletins in the (recent) past however, so this is all under some caveat until clear data from non-media sources (e.g.a USSTRATCOM TIP message) appears.
The map above is a preliminary map based on orbital elements from 16:35 UT, an hour before the reentry, and shows the approximate position for Phobos-Grunt for 17:45 UT. There might be some small discrepancy between the pictured position and real position as it is based on orbital elements from one hour before the reentry.
Note added 20:30 GMT: Confusingly, Ria-Novosti in a new press release mentions another time and position: 17:59 UT and the Atlantic, 18S and 311 E (49 W). This exemplifies what I mean above with the caveats....
Update 20:40 GMT: USSTRATCOM released a TIP message at 20:34 UT simply saying: "Object Decayed Inside Predicted Window".
That probably means: within the window of their earlier TIP message: 16:59-17:47 UT. This could be taken to support the 17:45 UT value of the Russians and reentry over the S-Pacific.