How is it delayed when they didn't ever give out a official release date?
They said sometime in Feb and that could just as easily be Feb 28th. Feb 4th was just a rumuor and that's exactly what it seems to be.
It was never delayed as there was no specific date mentioned but right now the build 8.15.12492.41 which is probably Windows 10 Technical Preview for Phones is being seeded out to internal testers in Microsoft according to Neowin (which is trustworthy).
One amusing touch in the update process for the new build can be found on the familiar 'Update successful' screen, which displays when everything is complete. Alongside the build number, it displays a quote from Seattle Seahawks quarterback Russell Wilson; a phrase that he uttered after the team lost the Super Bowl to the New England Patriots on Sunday: