There has been a TON of backlash about this decision. Lots of really ugly and, frankly, racist postings on fanboy message boards.
The entire point of the Ultimate Universe was to imagine what could happen if these characters were created today and could be explored with some modern themes and sensibilties.
Here is an article about the backlash:
Newsarama.com : Hey, That's My Cape! – Superheroes, Race, Change, & Hate
This all comes on the heels of Laurence Fishbourne being cast as Perry White in the new Superman movie.
Excerpt from the article:
For instance, over at The Beat, Heidi MacDonald posted the Spider-Man news and received an influx of racist and ignorant comments. Many were so bad she had to delete them and close off comments. Here’s one that remains:
“Political correctness run amok. Kill off whitey. Replace with multiculti. As a white person who has read and loved Spiderman my whole life, I am out. Will no longer buy Spiderman or Marvel. They could easily have created a new black/hispanic hero if they wanted to but this guy [Editor in chief Axel] Alonso changing a cultural con is a FU to white Americans. This is a FU moment to white people.”
I is sadface.