I have a Canon Lens 28-135 f3.5-5.6 IS USM and Tamron Lens 200-400 f5.6 (tripod mount recommended)
your welcome to use and or buy as ive changed camera system
Well, that's very nice to offer me this !

Still, I wonder if the 28-135 might cause blurry pictures because of the slow shutter speeds that I may get with f/5.6 at 135mm. I understand that this lens has a good IS system, but this doesn't prevent subject motion (and standing people tend to move somewhat during 1/30 of a second

).
Nevertheless, can you bring the 28-135 on saturday ? I will try to get as close from the scene as possible (and thus use my 85mm at f/1.8 and shoot at whatever speed this will give me at 1600 ISO), but if I end up farther, it might be better to take a chance and frame tighter at 135mm than cropping a 10 megapixels picture down to 1 or 2.
Are you with the other media people in front of what used to be the old control room ?
I may consider buying the 28-135 someday, but being a student, my budget is limited right now and I would even not be able to afford the nifty-fifty (50mm f/1.8 => 130$ ) . Feel free to sell it to someone else if you have the occasion, because I won't have that kind of money before at least January 2010.
What system are you using right now ? Did you changed because the lens you wanted was not available on Canon mount ?
Thanks a lot !
STL