I saw a comment on The Back 40K blog by a poster called Dodger3, he summed it up in context with the rumoured leak of the 6th edition rules, I quote;
"Flayed Ones are awful. They can Infiltrate, and they can Deep Strike, and nobody can figure out why you'd ever want to Deep Strike them. And then Imotekh--the most expensive HQ in the Necron book--came with an inexplicable special rule that would allow an enemy unit to act as a Locator Beacon for Flayed Ones. This did not help, as you'd still never want to Deep Strike them, ever. They were a bad unit given a useless deployment method which was then modified by a useless special rule on a pricey character.
And then, in the 6th Leak, all three of these things (Infiltrate, Deep Strike, and Imotekh's Beacon) have synergy with each other, and in a manner that is so clear it had to be intentional. Infiltrate is now a Deep Strike, but can ONLY make use of Beacons if the unit ALSO has the Deep Strike rule. You can charge (Engage) following a non-critical Deep Strike, and Beacons ignore critical range.
That's three different special rules, which were unknown to the public at the time, harmonizing to make a completely worthless unit suddenly become able to perform near-guaranteed Turn 1 charges when synergized with an expensive HQ."
Slightly off topic I know but I think 6th edition is where Flayed ones will become useful considering that the recent codex was written with 6th Edition in mind.
I have a friend who works for GW and he says that the deep strike rules in 6th are going to be very similar to the way it works in the alleged leak.