I don't think there's ever been an easier time to get rich quick in EVE than during the last week, with the introduction of skill trading. All of a sudden, the market had an item which was traded in higher volumes as well as isk totals than PLEX, something I doubt we will ever see from an item again in the game's history. The Citadel expansion probably will not even compare in trading potential to the introduction of skill injectors.
Unfortunately, I did not have too much time to play in the last week; but fortunately, I had enough time to make an easy 20b and rising on skill injectors. It really was as simple as "buying low, selling high," especially when, in jita alone, tens of thousands are being traded each day. On the first day I was buying injectors for sub-700m and selling them for 900m or more. I did transport some, and not dying did indeed help making a profit. I know quite a few other traders made many times what I did. The leaderboards on EVE-Mogul have a few traders making over 50b in the last month, and those are just the semi-public cases.
Even if you only have a few billion isk, you can still get in on the trading wave by buying 1-2 injectors (especially if you can get them for sub-600m right now) and waiting, or shipping them elsewhere, to sell for 700m or more. Buy them in jita, for instance, and carefully ship them to Querious or Khanid, where lots of active new players currently are, and watch the profits roll in when you sell them for 700-900m before you can even get back to jita to restock your orders.
The demand for skill trading is far higher than almost anyone predicted. (It does go to show that reddit in particular--which had a surprising number of negative threads about skill trading--is not often representative of the interests of the average players who log in every week, the many players who apparently love skill injectors and are driving the massive volumes.) Of course, there was a huge demand on the first day, which has since fallen off as players finished remapping their alts/characters.
The first week is over, so what will the average daily volume of injectors settle on? Obviously, it depends a lot on the price of PLEX as well as the general activity level in the game. The volume in jita is now dropping to sub-10k per day, which leads me to expect an average of 2-5k per day in March. I would expect the volumes of injectors to decline each week until 1-2 weeks before Citadels, and then spike over that month until falling again in mid-summer. With injectors, volume matters more for trade than prices (especially if you are willing to transport them).