Anyone know how regularly we should expect champion updates?

From Sion's completely overhaul to Maokai's pampering, does anyone have a clue on what times these could be released?

I'm expecting a tag team effort of champion releases and updates coming out back to back. With ever other champion update being more than the scale of Singed and Maokai.

If I had a choice of who'd get the Singed/Maokai treatment I'd put Shyvana up there. She could us some nice touching up and maybe a few adjustments on her abilities. Like how her W scales with AD but her E scales with AP. I can't be the only one that thinks that is silly. Also her in-game model just doesn't fit her splash art.

https://glamorousgamergirls.files.wordpress.com/2012/04/shyreference.jpg

http://3.bp.blogspot.com/-tG_A-rOhcnk/U_Z6cgBpf2I/AAAAAAAAV3I/zPligJCe3ro/s1600/Shyvana_0.jpg