Just bumped into this: (it shows the efficiency of wimax over other technologies such as HSPA,HSPA+ and even LTE for support for subscribers..of course it is done by intel who is an investor in wimax)
http://wimax.com/commentary/blog/blo...ays-intel-0315
By the looks of those papers Wimax can handle almost 2x the users that HSPA+ can so once more users start using HSPA and HSPA+ expect it to plum it while wimax will be effected less.