Saw this on a bears message board:
Just a note - they are saying on IRC that somehow the template Nike used got leaked, and now people are making their own jerseys and passing them off as real. The above stuff was confirmed there to be fake and 100% fan made.
*Edit* - Should point out that even if the template is leaked, that means the template indicates the cut on the jerseys that Nike is going for, which isn't something the team can veto.
So, disregarding the patterns and logos and colors and stuff, it looks like this is indeed the cut that NFL unis will be from now on - shorter sleeves and underarmor.