Does anyone know what will happen to minecraft's enchantment combinations system with the enchantment signs in place?

I'm asking because I've got a pile of weakly enchanted tools and eff4s.

Are anvils still working at the moment? If so, should I get someone to combine stuff immediately?

Will the signs replace anvils and have options for 'upgrading' tools, or 'adding' enchantments? (Ex: Adding silk to a tool that already has efficiency / upgrading an eff4 to an eff5.)

Should I be feeling sorry for people with extcreations?

I'm also curious about everyone's speculations as to what this will do to the exp market. I personally am kind of regretting selling my exp hoard...