It's a general problem with team books across the comic industry that's bugged me for years. In the old days writers would be satisfied having 1-2 members come and/or go each year with true shakeups happening every few years. They need to be satisfied hyping a new member joining, an old member returning or current member leaving instead of a completely new lineup every 1-2 years.
Real question for everyone who agrees with Hawkeye and myself on this; would you be satisfied if you knew the current 7 JLA members would not only stick around for a while but would take years for writers to slowly have them exit the title? Or would you accept a sporadic, no logical reason lineup change putting at least 5 of the original 7 back on the team?
I would be fine with a consistent lineup. I want to see them interact and develop as characters. I think, from what I've read of JLI, thats the reason why that team book worked as well as it did when it did. The constant team shakeups and characters leaving for their b/c of their own big events makes the book feel like it has no purpose and makes all our favorite heroes look like a bunch of flakey quitters. Honestly, I'm more excited for the JLI title myself.
It looks like we'll be getting a satellite era style Justice League and the JLI. So even though I am not a fan of the reboot, maybe this'll get the Justice League back on their feet.