What problems do you have with Leopard?
I'm not saying the OP has a valid need for Tiger, but I do sympathize... Suppose that I were an IT manager responsible for 5,000 or 8,000 seats, and so as it follows, I probably buy a few dozen new computers every week, and I manage (or my team does) the installed software, updates, etc, on all of them.
If Apple were to tell me that, today, on xx/xx/2008, I will now be running Leopard on all my new computers whether I like it or not, and I have zero grace to continue getting and using Tiger (or SL vs. Leopard or whatever), and my options are essentially to ... temporarily stop buying computers (not feasible), upgrade all my old computers immediately to the new OS so I have a uniform fleet (probably also not feasible), or else manage a mixed fleet, I would understandably not tolerate this.
In the Windows world, it's still routine to re-image these computers back to XP or sometimes even Win2k, because my job is to keep a bunch of office workers, most of whom don't really need the latest software, able to work efficiently. Of course Leopard is better than Tiger, and of course by this point, it's become quite stable and most of the compatibility issues have been resolved. But I think my efficiency concerns are not completely irrelevant.
But this is exactly what Apple says.
/rant ... sorry.