Lion will be coming out soon, perhaps as early as this week. We've created a new category for 10.7 hints, so go ahead and use that for submissions.
The good Macworld folks are also working up a few Lion specific add-ons for the site; more about that as it progresses. Whether those will be finished by launch time I'm not certain, but should be ready shortly thereafter.
There won't be a July hints contest as we get ready for Lion; this will give me a chance to get caught up on previous months (yes, I know I'm behind) and I suspect there will be too many good Lion hints to adequately judge them all. I'm trying to clear out as many of the non-10.7 hints from the queue before then, so don't be surprised to see some short, simpler ones.
Finally, just to let you know, I will be in the same situation as most of you; purchasing, downloading, and installing 10.7 from the Mac App Store on release day. It may take me a day or two to test incoming hints, as I become acclimated to the new system myself. So don't panic if your hint submission doesn't come out right away. :)
Mac OS X Hints