This information comes from neogaf and “idea man.” The man full of ideas is said to have connections with French game developers. He has talked about the Wii U thumbstick redesign before the new Wii U controller image was leaked. With all that said these are all still rumors.

First let us start with some Idea Man’s rumors we have posted before.

– Apparently, the titles & demos present at E3 2011 (maybe not all) were brought to the show on SD cards
– The port on the Wii U was made accessible for studios to run their content. I’m not sure if their projects worked directly from SD cards, or were then transfered to a flash memory or another storage to be launched from those instead.
– It seems no optical medias were involved at E3 2011. Wii U pseudo bluray weren’t there at all. Some people could have thought, for certain demos, with the little LED lightened, etc. that such discs were present in the drives and that these were working, loaded the data & all, but it probably wasn’t the case.
– With the latter information, it’s plausible that Wii U brought didn’t housed an optical drive. They surely were just the dev kits in a special form (surely the hardware removed from those big boxes and deprived of all the development stuff) with the activated at the time SD cards port.
– There’s also a possibility that for several demos (in roundtables, etc.), real dev kits (i think lherre talked a little about this in the first thread) were hidden behind, and directly plugged to the TV’s, with the software brought & stored through digital means (storage, flash, Host PC linked to the dev kits containing the content, emulating a normal drive, perhaps the hypothetic access times, etc.)
– About the optical drives, in the less likely scenario (see the last point + the following message in some days) that they were inside, they could have been not-yet-working-models, placeholders. This could indicate an optical storage situation still in flux at the time, still in the designing process.
– This could reinforce the hypothesis that the Wii U cases were just “mock-up”, boxes rather quickly built to contain and hide the hardware they intended to bring at E3. It’s a clear hint toward a possible change of the system appearance come E3 2012.
– Obviously, the situation has evolved since then, but not quickly after. This point will be made clearer in a following message about the optical storage of the Wii U.

Now here is a little more information from Idea Man.

– Third-parties studios are currently receiving (if it’s not the case, it will be very soon) Wii U “bluray” readers, writers, and discs.
– They must bring their projects on those Wii U supports at E3 2012. It’s an obligation, by Nintendo. It means the rumors that games could be brought through other means are false (or concerns only a certain type of content, like digital distributed titles).
– There was a delay, like the mass production dev kits, in their arrival. Studios were waiting for this equipment since several weaks.
– They didn’t came with the latest dev kits
– On the contrary to the mass production Wii dev kits (the green ones) that featured a disc drive, the Wii U still don’t have one. The reader is separated.
– No confirmation nor denial of 50GB discs capacity.

The Wii U units you’ll see at E3 2012 will include optical drives, and the software demonstrated will be loaded from discs inside those, at least for retail titles.

– Wii U games were developed on dev kits linked to a host pc (running the SDK, the development tools, etc.), and it’s possible the access/loading times were emulated, until now, as they will/have received the real support from which the software will be played. Let’s hope this drive will be fast enough.

– It’s not uncommon for developers to receive the medias, the storage of a new system rather late in its designing process. But here, the apparent delay is another element that could hint to a certain amount of time spent for either the engineering (physical modifications on the discs ? building of a proprietary file system that took longer ?), the manufacturing (burners, etc.) or the supplying, of these Wii U “bluray”.

– Wii and some other consoles have seen their dev kits sizes shrank with each revisions, from the first Wii big box to the last, very smaller (basically, a retail unit, i’m talking proportion wise). For the Wii U, it’s not the case, it seems the mass production dev kits have roughly the same dimensions that the firsts, only the color (and other things) have changed. And as they still don’t feature a disc-drive + as they are tagged final so the components are stable now, it means the internal volume, the heat & cooling situation, are the same as in the first dev kits (with overheat problems, placeholder chips, etc.), but this time with the finished versions.

Pure speculation but it could means that even with those really optimized components (maybe smaller chips process, etc.) the coolings needs are such that the dev kits size hasn’t decreased, therefore indicating positive info on the hardware capabilities. It could also be simply explained by a choice of Nintendo to keep the same type of boxes, materials (to save some fabrication costs), and just pimp it quickly to another color and that’s all.

– The fact that these latest dev kits aren’t incorporating a drive could means that another revision will launch after, certainly like the Wii green models, designed like the retail console, and with an optical drive this time. But as the recently arrived kits are tagged “mass production”, these hypothetic following models certainly won’t come with extensive hardware changes.