So I was taking a quick look at the FAQ (http://forums.battle.net/thread.html?topicId=27800569797&sid=3000). With level 5 gems being the highest level gems dropping from monsters and its going to take 19683 lvl 5 gems (based on some quick math its 3 gems to upgrade to next level) to make a level 14 radiant star. I know the devs have said that stashes and shared stashes are going be huge, but gem storage could take up a HUGE portion of our stashes.

First lets assume you have some level 4 gems as well as level 5 gems, since the common gem drops in D2 were flawless and not perfect gems even though perfect gems could drop. We could potentially have a maximum of 2 gems per level 4-13 for each type or 20 gems of each type. With 6 different types of gems according to the wiki (http://www.diablowiki.com/Gems), that means that we could need to have up 120 gems in storage at a time. Once again I know the stashes are supposed to be huge, but that's a hell of a lot of storage JUST devoted to gems. Add in wanting to be able to hold talismans, runes, and gear into the equation, and we would need a truly outrageous amount of storage.

Adding runes into consideration, we know currently there are 5 types and 8 levels of runes (http://www.diablowiki.com/Runestones). Assuming 3 runes to upgrade to next level (even though we don't have this confirmed yet) and that we will likely only hold onto level 6-8 runes that drop in hell mode. Thats another 20 slots to hold just level 6-7 runes of each type. While this isn't nearly as bad as the gem situation, it still eats away more storage space.

Did anyone get to see how big the storage really is during blizzcon? Will the storage of all these gems be taken care of by the Jeweler artisan? Is there just more info on this that I haven't read yet?

We'll probably be dropping gems a couple levels further than the 5th (as previously stated), which should help. We also want to make sure it doesn't become a pain to have a ton of gems sitting around waiting for another one to upgrade, so there may be some crafting solutions that help with that. But more importantly we expect a more robust trading system will make it much more feasible to sell off a ton of gems, earn that wealth, and then buy back into gems later when you want - and on the buyer side of that, if you have some gems and just need one more to upgrade, it will be quick and easy to go get one for a reasonable price.