Some predictions off the top of my head:
- Trophies wouldn't exist.
- PlayStation gens would've been longer than they were.
- PlayStation consoles would've been more expensive for longer.
- PS4 would currently be approaching the DS/PS2 sales range.
- PlayStation online offerings would've been much slower in terms of roll out (but things like Plus still have come into force regardless, with Sony taking more inspiration from Steam and then TV/movie streaming services, rather than Xbox Live).
- Better PSV support.
- Fewer acquisitions by Sony.
Not sure much changes for Nintendo; the company does its own thing even with MS in the picture, but:
- Perhaps Nintendo home consoles would have received more third party support (and the tech gap would've been smaller in this other timeline, making it easier for third parties to make games for both).
- WiiU would've probably sold better.
- Nintendo's online development would've been even more glacial.
