HD consoles sold HD TVs this generation. Many people wouldn't have upgraded their sets as quickly if not for the consoles requiring a TV with a much higher resolution in order to enjoy the best experience with them. Granted not all TVs sold were Bravias, but I bet some were. Likewise if the Sony PS4 can do 4K video playback, then a PS4 might sell a few Sony 4K TV sets too. It's always better to have at least something actively trying to drive sales for your business arm than nothing at all.
4K video will help Sony TV/movies... but significantly? probably not, especially in the short/medium term.
(selling the same movie to the same person but "in 4k" is obviously profitable, as-is selling some more 4k TVs... but the problems of the TV division are reportedly much deeper than this)
If the PS4 becomes a breakaway success like the PS1/2 was, or even if it just manages to sell of the order of 80-100million units is its lifetime, those are all platforms through which Sony can bring in more revenue to their media businesses by pushing content on said device. Additionally, if PS4 has voice recognition, some fancy camera and handsfree UI control functionality, then these are all things that can be provided by the PS4 that "enhances" the consumption of Sony pictures/music content, uniquely driving sales for those business arms through a means that requires no sharing of those revenues with external platforms/companies/3rd parties.
Sony's 'Video unlimited' service already supports:
- BRAVIA® Televisions
- Blu-ray Home Theatre Systems
- Windows-based PCs through Media Go
- Xperia(TM) Mobile Phones
- Blu-ray Disc(TM) Players
- Sony Internet TV powered by Google TV
- PlayStation®3 Systems
- PSP® (PlayStation®Portable) systems
- Sony Tablets
The PS4 will certainly support movies/music, but neither the movie nor music divisions will be worried if Orbis fails spectacularly.
(I'd also suspect that most 4k TVs are smartTVs - which makes the whole concept of selling content via a PS4 a bit weird)
Even Sony electronics can benefit from a PS4 that is designed to somehow interface with Sony phones, e-readers, Vaio laptops, cameras, camcorders etc etc. If the functionality added is appealing to consumers, and can drive the uptake of those products through their association with the PS4, then its a good thing for Sony's business.
The success/failure of Orbis is absolutely *key* to Sony's gaming division. Sony have a lot of money invested in a lot of studios that need to produce content for a platform - and given the state of Vita, that platform has to be Orbis... If Orbis fails then "downscaling" seems highly likely.
For the other Sony divisions, there's a potential for a marginal advantage if Orbis succeeds. If Orbis fails, it doesn't make any huge difference to their profits.
Strategically, financially, Sony need a successful "games console". They don't really need yet another home entertainment device.