Nishi is very top 10 material so I agree. If not now at least in the near future.
I also see a few moving up like Cilic, Nishi, Querrey perhaps, Dimitrov, Janowicz, Paire (his rise is very gradual though), Klizan, Tomic, Harrison etc. Some say Fognini is due for a move up. Perhaps Goffin too.
There will be some new ones as well - those are the unknowns - very hard to guess.
Fognini is easily top 30 material and would be if not for missing a large part of the beginning of the season last year. Cilic likewise (in terms of missing a large patch), forgot about him. Both players misses the AO last year I believe.
Klizan is a bit inconsistent, mentally a bit weak, as proven by some of his chokes last season (four Championship points in a Challenger tie-break, lost seven of the next eight points). I do like him though, really hope he can continue to improve. He's defending a lot of points around the USO though so needs a strong first half of this year.
It will certainly be interesting to see who the next players are to crack the top 20. In this day and age it tends to be older players (like Tipsarevic and Kohly) who really push on from the 40's and 50's, or players on injury comebacks (Monfils will surely be back in the top 20/15 if he stays injury free). Younger players like Tomic, Harrison and Dimitrov seem to stall, often showing flashes but struggling for consistency. All three have had good starts to this year though (semi-final, quarter-final + first top 15 win, final).
I'm really looking forward to see how Janowicz fares this year. I still hold the opinion that he's out of position due to the somewhat farcical Paris Masters, although his talent is not deniable. I think most players inside the top 40 could beat him, especially outdoors. Will be interesting to see if he can really live up to his new ranking though or if he does struggle a little bit.
I can definitely see a win over Fed on the horizon.
But Nole?.. You think?
Milos' movement is like the original game of Pong compared to Nole on ice skates.
Same could be said of Andy, and Raonic has beaten him twice. When his serve is on song it can frustrate the likes of Andy and Djokovic, more so Andy though I think. Djokovic is much more consistent but Raonic could definitely take him on an off day.