I TOTALY AGREE
I myself can need 3 pages for nice fast playing, could even use more but for so specific champs like jax i can just get on with it and change one page. I planed on geting one rune with cd reduction and magic res(blue)/hp and mp regen(yellow)/magic pen(red)/flat hp quints(this one is mostly on casters/heavy mana users), second would be same but without mana regen and with armor(for kat my fav hero so far) and third with armor pen in exchange for magic pen. I could even make third page for mundo/tryn, with armor pen and wtihout mana regen.
But i can't, so i must change runes often... and mostly i just waste that mana regen and play mundo with it... couse i chose champions based on my team.
BIG +1 FOR IDEA
I think 4 or 5 pages would be good, mage/fighter/tank and 2 or 1 is left for specific build or hero.
EDIT: And for ppl who think it's not needed. IT'S NOT NEEDED FOR YOU. Some ppl like me play mundo/rammus/kat/shaco/udyr/nidalee/nasus... and so on and so on, i hate playing one hero, it's boring. But for nice, fast and enjoyable playing i would like to have just 1 or 2 more pages ;/.