There were some presentations at the last in power conference which explain this better than I can, but the directions from Mercury has changed.
Mercury will be a brand new product targeted for new applications and it's initial focus will be on applications such is handling trouble tickets. Any app where somebody raises an issue and it has to be processed through to completion.
Mercury is not intended as a new UI for existing applications and there will be no concept of a conversion tool.
Mercury will be targeted at new app builders to improve the chance of success. QuickBase has found that many first time users try to develop an app and give up. So from a marketing perspective it makes the people at QuickBase crazy that they lose these opportunities to grow their seat count. Hence the new direction for mercury to have a very simplified at building experience. But the initial features for mercury will be much more limited to what we see now in the very mature functionality of Quickbase classic
So it is full speed ahead on development for QuickBase classic, the version of QuickBase we all use today. You have no doubt notice me the frequency of updates of late, and that is evidence of the engineering investment that QuickBase continues and will continue to put into the original QuickBase product.
At this time, nobody, including people at Quick Base themselves, really know whether there will be a convergence of Mercury with classic Quick Base sometime in the future.
Having said that I seem to recall the EMPOWER slides talked about some kind a beta testing in the fall and general availability in the first or second quarter of 2018.