I've recently started playing the beta and I have to say the game is great, but I have a couple of suggestions to Riot of how to improve some of the item interface.
Currently there does not seem to be any method of storage, where if you're out of inventory space you can place items that you need for combinations or such away for later use. If you're out of space for new items you need to sell your old ones and if you have a decent build that can be a real problem.
Another issue I've encountered is the use of consumables. If you're planning on using consumables you need to waste inventory spots that could be critical for the stat boosts you can gain from items. My suggestion is to put a small 2 or 3 slot extra bar that can only be used for consumables and is hot-keyed by numbers (i.e. Crystal Water on Potion Slot 1 can be used just by pressing 1).
Overall I think the game is great and these are only suggestions, but I think they would add a new layer to the strategy and gameplay of LoL. Keep up the great work Riot.

I don't feel like you need to have a storage area because you can just wait til you have enough money for all the pieces if you only have one space.