The iMac is too far away from the tv to be hardwired, so I'd like to use the iMac's bluetooth technology.
I have very limited experience with BT in my home theater--before the iPod touch I used an Apple BT keyboard--but I think you'll find that you can successfully run cable, be it VGA, DVI, HDMI or ethernet, over greater distance than the max effective range of bluetooth.
So, while other reasons may still be perfectly valid, like you don't want to spend the money buying a long cable run if you don't have to or you would prefer that everything "just worked together magically" over the air, but, if BT could theoretically work for you, it follows that the "too far away from the TV to hardwire" excuse probably isn't valid.
Is there a way that I can go to a web page (i.e., hulu) on my iMac and bring up and play a television show, then use bluetooth to send the television show from the iMac to my PS3, and then use the PS3 to send the television show to my Pioneer?
I don't own a PS3, but I don't think you have any chance of achieving this until ultrawide-band and wireless USB gets further along, and even then it might still be a pipe dream. Here's why--at the moment bluetooth can do what, 3 Mbps, max? That means it's significantly slower inherently than "g" wireless at 54 Mbps max. In real world use, we all know "g" operates significantly slower than that, at times it could barely handle playing back "easy" video over a "g" wireless network without stuttering. And, with VNC/screen sharing between two Macs over a WIRED gigabit network, I think you'll find you can't start playing back a video on one Mac and "watch" it in the screen sharing window on the second Mac, without stuttering.
I've heard suggestions like playing the shows directly on the PS3, but for lots of boring reasons, I definitely want to use the iMac.
Right, Mac owners who do try to use their PS3 as a media extender do so by running third party UPnP applications to stream recordings and files over their home ethernet network. Look into MediaLink, EyeConnect, TwonkyMedia et al.
Also, you should know Hulu is pretty demanding for a Mac, so if that's a priority for you your best bets are probably to 1) try running a long length of cable to the TV, 2) get an aTV and hack it to do Hulu--if that's even still possible, or 3) buy a mini for the TV.