The recent number of E74 error reports by Xbox 360 owners has dramatically increased since the release of NXE late last year. There has been no confirmed link between the two, but Microsoft has published a support document this morning that details that the E74 error would now be covered by their free replacement warranty like the RROD error has in the past.
Previously only a 3 ring error code was covered under this extended 3 year warranty. The E74 has become much more prevalent and Microsoft is no doubt trying to proactively head off any potential lawsuits that may stem from further hardware issues related to Xbox 360 consoles.
Dean Takahashi has some additional data concerning the increase in E74 reports as well as some first hand accounts from people that have experienced the E74 error.