Looking at this again after a year, a lot has changed (liquidity & transactions). Now I'm curious with Dan talking about EOS, will another exchange put their platform on BitShares just as Openledger did? This could solve the issues Poloniex has been facing.
Take a look at this chart (It takes a long time to load the data):
http://cryptofresh.com/chartsI don't think there's really a need for another exchange to come aboard Bitshares at the moment. The market isn't really big enough, and it will hurt market depth by fracturing it off inbetween multiple exchanges' IOUs.
I think Bitshares needs to reconsider sidechains if it wants to stay one step ahead of its competitors. More decentralized DEXs are coming (blocknet), and there are a couple other DEXs that now exist and/or will be here soon. Waves (IOUs like bitshares), Supernet (multi sig), Blocknet (atomic swaps), etc...
At least Bitshares has bitUSD and the like, so even if its DEX ends up not winning the DEX wars bitUSD could be a useful instrument for other DEXs.
It will be interesting to see what technology wins out.