There's been speculation floating around the web already as to why the event might have been put off. To some it's in mourning of Apple co-founder and former CEO Steve Jobs.
Or it could be even be ditching the hardware Samsung has built (hence the 5MP camera rumor?) and going for a more advanced setup. We've seen it happen as a response to an Apple announcement before. When Apple announced the iPad 2, Samsung had just announced their original Galaxy Tab 10.1 at the MWC 2011 but they were quick to rename it as the Galaxy Tab 10.1v and later on discontinue it. Several months later they came up with the slimmer and cheaper Galaxy Tab 10.1 that we now know.
While waiting for the next announcement, why dont sit down and enjoy the Nexus Prime leaked?