I though I'd paste a link to a Dev blog indicating whats been going on in Jita recently. Just in case any readers havn't seen/read it ! Basically over the last few expansions the Dev's have been working flat out to allow Jita and other busy systems to scale better.
Result: You can clearly see from the graphs linked above they have been successful - and I must congratulate them on finding such an improvement from changing the Inventory system.
Basically this is showing the Dev's are just as interested in making the game scale - in that they are fixing long term problems as well as making the "new shiny" features...
Not many MMO's release the tech detail CCP does on its Dev blog - I really wish more would..