I read your "how this is different than a spreadsheet" blog, and none of the examples struck me as compelling, even though I use my Excel/SQL toolchain every day. Given how strong the ecosystems are around those tools, I think it would be very challenging to convert power users without some really obvious hook.
That one hook COULD be a good mobile client. For example, I have a dashboard built in Excel with an ODBC connection to a few of my company's DBs. However, I obviously can't see this on my phone, since no mobile Excel client supports ODBC (not to mention the macros I have built in).
I could maybe see a "disruption" angle, where you provide 75% of the functionality of Excel+ODBC+SQL+Workbench in one easier to use package, but I wonder how large the market is for people who want to work with that level of data but don't want power tools. I guess that's one area where you'd have to trust your market research/gut.