I don't think Perry can become Nick Collison. Collison was a much better collegiate player than Perry is. @ralster pointed out the size difference. I would go further. Let's compare career numbers:
Freshman Year
Ellis - 5.8 ppg, 3.9 rpg, 0.6 apg, 0.3 bpg, 0.4 spg, 47% fg, 67% 3p, 74% ft, 13 mpg
Collison - 10.5 ppg, 6.9 rpg, 1.1 apg, 0.9 bpg, 1.1 spg, 50% fg, 38% 3p, 67% ft, 22 mpg
Even accounting for the difference in minutes, there is a huge gap in production between the two. Collison was a decidely better freshman, as evidenced by the fact that he was able to garner 22 minutes while Ellis only merited 13.
Sophomore Year
Ellis - 13.5 ppg, 6.7 rpg, 1.0 apg, 0.6 bpg, 0.8 spg, 55% fg, 47% 3p, 76% ft, 27 mpg
Collison - 14 ppg, 6.7 rpg, 2.2 apg, 1.6 bpg, 1.1 spg, 60% fg, 40% 3p, 62% ft, 27 mpg
Their sophomore years are similar in points and rebounds, but Nick doubles Perry up in assists and blocks, and shot 5 percentage points better from the field. Perry exhibits the better range, but you can start to see the Nick is much better inside.
Junior Year
Ellis - 13.8 ppg, 6.9 rpg, 1.2 apg, 0.7 bpg, 0.8 spg, 46% fg, 39% 3p, 73% ft, 29 mpg
Collison - 15.6 ppg, 8.3 rpg, 1.7 apg, 2.2 bpg, 1.1 spg, 59% fg, 37% 3p, 57% ft, 27 mpg
And now we see the separation. Nick has continued to improve, boosting his points, rebounds and blocks, keeping his FG% steady. The only thing that took a dive was his FT%, a fact that would haunt KU the next season. Meanwhile, Perry puts up a season very similar to his sophomore campaign, only slightly less efficient.
Senior Year
Ellis - (through 10 games) 14.7 ppg, 6.2 rpg, 0.8 apg, 0.1 bpg, 0.7 spg, 53% fg, 41% 3p, 74% ft, 26 mpg
Collison - 18.5 ppg, 10 rpg, 2.2 apg, 1.9 bpg, 1.2 spg, 57% fg, 34% 3p, 63% ft, 32 mpg
Collison was the horse that we rode to the national title game that year. A lot of people only remember the horrible FT shooting in that game, but you have to remember that Collison (and Hinrich) basically carried that team to the title game in much the same way that Robinson and Taylor did nearly a decade later. Ellis has taken a small step forward this year, but unless he goes crazy in conference, he's not putting up anything near what Nick did.
If KU is to go to the Final Four this year, it likely will not be because we ride Perry Ellis there. More likely we ride Selden and Mason to the Promised Land if that's where this party ends up.
Perry is a very good college player, but let's not forget, Nick was a great one.