Some people asked me recently how sure it is Oracle will continue support and developement of Apex. Never say never, but the fact that it comes pre-installed with XE and the 11g database tells already something.
But the most striking fact for me is that Oracle development uses Apex themselves as part of their database solutions. Oracle Vault, the build-in auditing tool, uses Apex as reporting layer. Just have a look into the online documentation. Interactive reports, someone?
