They need to make a potion that you can store your levels in. That way if you die you don't loose all your levels as long as you "stored" some in potions. To make one all you would need is a bottle of water and for ingredient you would use your levels. Each bottle of enchanting could have 20 levels stored in it t a time. The actual item would look almost like exp orbs but in the bottle.
I guess its cool, but on MAJOR problem. How could you possibly make them? XP isn't an item, so it eliminates crafting tables. And brewing stands wouldn't work cause of the same reason. The only solution would be to make an entirely new type of crafting table, which would be a bit pointless since it would be for just 1 item. So really I like the idea of it, but no support.
I consider Experience Points a very valuable 'material' in Minecraft. Since they have the capability to store powerful enchantments onto your tools and armour, using certain levels of experience. Having the ability to store it sounds a little OP, since you are most likely to earn more experience than usually loose them at a certain point in time. I think it's already best enough how a portion or half of your experiences is dropped on death, making it more balanced.