Some online retailers are listing revised launch dates for both titles.
NeoGAF Forums user DarthButcher has posted that, according to his retail sources, Metroid: Other M and Sin & Punishment 2 might be delayed.
Apparently, some internal retailer lists are showing Metroid as changing from a June 27 date to TBD, while Sin & Punishment 2 has moved from its original slot of June 6 to occupy the June 27 date. On the web, Wal-Mart now lists Metroid: Other M as releasing on September 1, while Best Buy has it pegged for August 15. Best Buy also lists Sin & Punishment 2 as a June 27 release.
No official word has come from Nintendo themselves, and their release lists have not changed. Nintendo World Report will have more updates as they break.