No way I don't think Ovtcharov has it in the bag at all. The young french and german players are very promising, Gauzy, Robinot, Franziska etc I think Patrick Baum has a better shot at rising into Boll's shoes than Ovtcharov
Don't look down on Ovtcharov, he stretched Xu Xin to 2:2 recently and also during the 2011 World Championships, he was the 3rd player to get 2 sets off Zhang Jike besides WLQ and Wang Hao. His service is pretty lethal(even Ma Lin agreed to that), and his mid-range looping is extremely powerful, especially his BH and I would say that it is more powerful than Boll's looping in terms of his penetrating power(both BH and FH).
The only thing that lets him down is his horrible short game(non-existent FH push, weird looking half-long BH pushes which gives away too many free points to opponents). However, he does master that BH over-the-table loop pretty well(much better than the other Europeans IMO), but you can't do that for every single serve, and you need more variation in the receive. Also he has a bad habit of trying to kill the ball(getting out of position and balance), even when the opportunity doesn't look that good, which causes him to make a lot of unforced errors.
In essence, when he learns to incorporate finesse in his game, that is when he is going to really shine. Zhang Jike used to have this problem too, being impatient on points and trying to loop-kill every single shot(back in 2008-2009), and as a result didn't do very well. It was when he started seriously cutting down on power and focus on finesse(his coach always asks him to resist the opportunity to kill the ball, focusing on consistency instead in his reportage). Now when he plays, he doesn't loop-kill every ball but works very hard to get the opponent out of position, and he only kills the ball when there is a room for error, or when he is on fire. As a result, he makes extremely few mistakes and puts a lot of pressure on his opponent, who often makes more mistakes than he does.
In this respect(finesse), Timo Boll is so much better, very consistent, very few unforced errors. If only Timo could have Ovtcharov's power and Ovtcharov could have Timo's finesse in their game, the Germans would be on par with the Chinese now.