Apparently, there would've been crossovers.
I kinda do wish he'd guest at the end of the series. Like, a 3 epi arc or something, leading up to the finale.
They could do
something for Jess for three epis right at the
end...like, ya know, have him come for Luke and then end up winning Rory over again...
They really didn't make a deal of it. She's a blubbering, in denial, moody monster about Dean the first time, she sobs about Dean the second time--and that's AFTER she admits she likes Jess...but Jess...
nothing. 
There are so many things bad about season 4 (HATEHATEHATE), but the lack of Jess was one of them.
