Here is a June 11 Rivals report on Ellenson--note the "five-star" reference at the end:
CURRENT RANK: 56
How many big guys have shown more improvement than Ellenson? He has very good size, is a good athlete and rebounds at a very good clip. The biggest change for Ellenson has been markedly improved mobility and conditioning and there just aren't many bigs who can run with him for an entire game. His motor is non-stop and he has very good skill. He does settle for a few too many deep jumpers at times, but he looks like a safe bet for five-star status.
If Ellenson is actually looking seriously at the Huskers, this development is a sign of huge progress by Tim Miles & Co. on the recruiting front.