It depends on how you balance it, either he’s doing good to keep up with his team mate since entering the team w/o any testing or previous races (half the season had past) or he’s not living up to the hype around him (looking past the fact he’s in the worst car on the grid)
I think its the former, the kids doing ‘ok’. Nothing better but nothing worse, if he’d started the season with HRT (or anyone) then it would be fairer to judge him by now. Perhaps by Brazil we can say with more certainty, but for now im reserving judgement.
Do I think he’l be in a Toro Rosso or Red Bull next year or after? No. STR is likley to be sold within the next 2 years (In my opinion), and RBR will be stupid to put a rookie in as Vettel’s #2.