"sales figures" ...
RDBMS isn't going anywhere. Sales figures will continue to be computed by a SQL query processor and archived on other systems such as data warehouses.
Has XML lived up to its promise? What were those promises? How about "data everywhere?"
1. Is the data available by a consistent standards-based interface?
2. Is the data consumable by a consistent standards-based interface?
XML has done a good job satisfying the latter but not the former. HTTP is closest to satisfying that goal but it is too open ended. SOAP has failed due to its (very much intended) complexity.
XML has not lived up to its promises. However, if you look at RSS as a publishing mechanism, it has succeeded very well.
How about an RSS feed for updated sales figures? I use RSS to track new CVSNT releases.
Why not highly targeted RSS feeds? And, if they are not highly targeted, why not have RSS feeds that accept a query?
Is this better than using SQL*Plus? Damn right it is. Can I write code to get the data via RSS? I sure can. What would my application do with the information? Who knows. How about making an RSS feed for current stock prices?
Are there other solutions to RSS/ATOM? You bet. Pick your poison (API). The advantage of RSS/ATOM, like ODBC and JDBC, is that the interface is well known and tons of free software, sample code, and tools already support it.