Wondering if there were possible connections, I wound up looking at Debkafiles, which is a pretty "caveat emptor" outfit that does often point in interestint directions. They say that al-Qaeda has made attacking the Gulf states a higher priority, a claim based on Saudi militant publications which suggest the jihadists feel too much emphasis is being placed on Iraq. Oman's detainees, however, are predominantly from there, and are Ibadhi rather than Sunni Muslims.
Those arrested in Kuwait, however, have included people of several nationalities, and while I can't find it now, several said under questioning that they had crossed from Iraq. DEBKAfile claims they were from Fallujah and Ramadi. They also claim, unsupported by anyone else whatsoever, that a new terrorist group called "Returnees from Fallujah" recently caused a security alert in Jordan. This possible Iraq connections is what concerns me, as it suggests fears that Iraq is becoming a new breeding ground for terrorists are well grounded, and that these terrorists are already moving within the region. This also has implications for the conflict between the Republican view that the most important element to fighting terrorism is rogue states which sponsor terrorism, as opposed to Democrats' emphasis on failed states which become havens for terrorism. We should find out more in the coming weeks as these situations develop further.
UPDATE: Praktike has a source linking Kuwait's militants to Iraq.