Wirelessly posted (My IV to the Net: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0) BlackBerry7250/4.0.0 Profile/MIDP-2.0 Configuration/CLDC-1.1)
I believe this was discussed in the last year or so and it seemed like the general consensus was that as a business traveller staying at higher end properties your company is paying for everything so tacking on a fee for HISA is accecptable, to the hotel.
And since everyone pays for it, they will continue to charge it.
HI are the only properties where I am not seeing the charge, across the board. I do not stay at HGIs though so can't speak to those.