The reason we've never heard about any of this, apparently, is that the US is not advertising the operations, the al-Bashir regime in Khartoum has declared a media blackout, and Egypt is respecting the blackout but keeping a close eye since this involves major arms traffic (it's an old route, once used by the French poet Rimbaud) going through its territory. Today al-Shorouk said that an Egyptian intelligence agent visited the area to verify the issue.
I've been talking about this with a few people who closely follow the news yesterday and we're all rather skeptical at this point. Some of the Egyptian press (not necessarily al-Shorouk though, as far as I know) has a bad reputation for pulling things out of thin air or basing them on unreliable disinformation websites like Debka. This would be a huge, world scoop if it turns out to be true, involving so many of the region's hottest issues: arms trade, illegal US operations, Hamas' supply line, Iran, Sudan and its recently indicted president. The story also assumes that a convoy of trucks carrying weapons (presumably the Grad rockets Hamas is launching against Israel) are able to make their way through Egypt, which seems impossible without the cooperation of the government or serious wasta up high. (That being said, drugs use the same route, and small arms did come from Sudan during the Islamist insurrection of the 1980s and 1990s.)
So basically, either al-Shorouk got it wrong, or it has revealed the first secret military actions of the Obama administration to control the arms smuggling to Gaza issue - as the Bush administration had promised Israel in the MOU it signed in mid-January. I'm a skeptic, but I'll be watching how this develops.