They don't support blu-ray because they don't want to advantage Sony, even if not in the gaming department. The same goes for Microsoft, why did they suppoerted HD-DVD? They do not own any format or any film company. It was just because they didn't want Sony to succeed. It is clear that all the blu-ray thing on Ps3 was not meant for gaming, in terms of gaming the blu-ray (despite what some sony developers say) has been a problem it increased the hardware cost and it delayed the console launch, also I've yet to see a multiplatform game to be canned due to DL-DVD limitations. But blu-ray is the core of Sony overall strategy, they use it to sell movies, to sell HD TVs, now to support 3D products. It's clear that both Nintendo and Microsoft as direct competitors doesn't want to support that. Also, using an uncoventional format, is supposed to be a good way to fight piracy.
As for DVD, it may simply be an image issue. Releasing and HD console in 2012 that actually only supports SD content will make it look outdated, so they just say its not a device meant to be a movie player. The DVD wouldn't be a selling point anyway, (thought blu-ray is another story). I just can't imagine an HD TV standing in a living room still without a DVD player.
That's not to say I'm happy with their choice, btw.

As long as we get a Netflix channel like the Wii has, I will be happy.

Its not so much about adding another DVD/ Blu-Ray player to the mix ,its more about being able to buy media knowing you can use it in what ever machine is the most convenient to you at the time.

For people that already disagree with Nintendo's philosophy, this will be a place they can aim their concerns. For those of us that like Nintendo, this will be a place we have to defend. For the majority of people that are on the fence or unknowing of the system, they will not care.

Evidence is in this generation. While some may say DVD playback moved the Playstation 2 (even though sales patterns seem to say otherwise), Blu-Ray and DVD/HDDVD playback did not move consoles this generation. What will get the new customer/casual is not if it can play BluRay or DVD's. I never heard anyone in this past generation say, "Does Wii play DVD's? No? Well lets buy a 360/PS3 instead..." and I am pretty sure not many of you did either. It may be a cool feature, but it is NOT a selling point in a video game console.

oh well. i never use most of the multimedia features on my consoles anyway. just one unnecessary feature the WiiU wont have.