In previous regenerations, we either have had a Doctor who is mostly active after his regeneration, but is slightly physically and mentally unstable (Troughton, Tom Baker, Colin Baker, McCoy, Mcgann) or a Doctor who mostly needs rest ( Jon Pertwee, Davison and Tennant, mostly, although Tennant was active in the mini episode he definetly needed rest for most of The Christmas Invasion). Of course we don't really know what happened with the Eighth-Ninth, but if the regeneration was recent if "Rose" seems to indicate, then he definetly was active as well.
From the initial preview for the series, the one that showed clips, there are several scenes from what appears to be the Eleventh Hour, mainly Smith going around in Tennant's clothes and looking very active. I think he will be fairly active, although apparentally there are some scenes where he's still feeling the pain of the regeneration, if set reports are to believed. (One leaked line is apparentally him saying "I'm not done yet!" referring to his recovery).
From the initial preview for the series, the one that showed clips, there are several scenes from what appears to be the Eleventh Hour, mainly Smith going around in Tennant's clothes and looking very active. I think he will be fairly active, although apparentally there are some scenes where he's still feeling the pain of the regeneration, if set reports are to believed. (One leaked line is apparentally him saying "I'm not done yet!" referring to his recovery).