I'm against upload limits I'm afraid. I process my photos as and when I have the time to do so, and as I work shifts, I may well have the time to upload 10 or 15 today, and then none for a week or more. In any case, I don't believe it's the sheer quantity of pics that's the problem, as the screeners generally get through the HQ material within 48 hours or so. It is the QUALITY of the material. If it was all high quality, it would ALL get added by the screeners and we'd have a queue of 0 pics waiting for Johan.
OK, there are plenty of new or inexperienced photographers (or experienced photographers who are just getting to grips with digital versions of their images) who struggle to produce pictures that meet the quality threshold. But for those of us who are regular contributors, we should all have a feeling by now of roughly where the quality threshold is (OK OK, more or less, anyway), and choose to upload the material we feel meets the acceptable standards. This doesn't mean we should be getting 100% acceptance, but we shouldn't be clogging the queue up with our poorer pictures, especially if we think they might get binned in the end anyway.
Look at what Vasco posted above: "763 photos and 182 photographers..." ahead of him in the queue. That averages out to only 4 photos each, and we all know that some photogs will have a lot more than 4. So a significant amount of the pictures in the queue will be in ones and twos per photographer. So how is limiting the regulars to 10, 15 or 20 photos going to help? Most regular photographers ought to be getting most of their photos added via the HQ option by now. So they can best help the queue situation by uploading quality material, rather than A.N. placing a cap on what EVERYONE uploads.
In another thread, the idea of "HQ" photographers having all their pictures either added by the screeners or else immediately rejected without going to Johan has been discussed. How about this: When you have more than xxx photos in the database (what do you think: 200? 400?), you automatically become a "HQ" photographer - and anything not marked as HQ by the screeners automatically gets bounced back to you. This way, the less experienced photographers get their borderline cases reviewed by Johan - everyone else gets either an instant acceptance or rejection without clogging up the queue.
Anyway, apart from all that, consider this point. A (new?) photographer uploads 10 images - all get sent to Johan. He now gets frustrated because they're not going anywhere. He also can't upload any more pictures - because his existing ones are still sitting there. He's now doubly frustrated. We get more "what the hell's going on with my photos?" threads posted in here. Eventually the frustrated photographer whose pictures are not getting added and who can't upload any more while they're waiting goes elsewhere because it's not worth uploading to A.N.