Hello, I had a talk on IRC and did a quick view on what this 6.2 firmware updated. I think it's a massive clue to how the Gateway is operating; The firmware modules updated WiFi things as you'd expect.. and THE DSI FIRMWARE! The blue card i believe spoofs a DSi-enhanced game (doubles as a way to get around the flashcart check if so

), the DS mode 'installer' puts something along these lines on the real SD
http://drunkencoders.com/2009/08/dsi-hack-update/ - tells you to reboot, the cart has been told to boot into DSi mode now, and executes the savegame hack!
There must be some reason DSi mode is then some way tricked into jumping into 3DS mode protected memory, that part we can only speculate on (prehaps similar to how the Gamecube memory allowed the Wii to be hacked). So the entire hack is possibly 3 different exploits in a way -> (DSi kernel, priviledge escalation twice to 3Ds user then 3DS kernel).
So the 'entry point' they talked about, indeed would not have been blocked until yesterday (just after the review units have been sent out no less). The reason it's limited to only 4.5 is because 5.0 patched multiple kernel level vulnerabilities .. but this means the possibility of Gateway having up to 6.1 support is not unfeasible prehaps and shouldn't be written off, very interesting..
Also it would explain why they originally said nothing about 5.0 not working.. they probably do have 2/3 of the steps needed and maybe even were running games in their 1 game per SD method on 5.0, it possibly doesn't require to go above usermode... once 6.0 dropped they were caught by surprise, when they could have been compatible with all firmwares. So they changed plan.
Hope that all makes sense but i believe it's a good more accurate guess at what is going on and the confusion behind their decisions.