No, it doesn't imply that they own the IPs at all.

Here is a list of Sony owned franchises:  http://en.wikipedia.org/wiki/Sony_Computer_Entertainment   

If that's not enough for you, get a copy of a Ratchet game, look at the small print on the back of the case, and it will clearly state that Ratchet is a trademark of Sony Computer Entertainment America.

Insomniac didn't even develop the portable titles (Size Matters, Secret Agent Clank. They were developed by High Impact Games and published by Sony. That wouldn't be the case if Insomniac owned the IPs.

Seriously, I thought this was common knowledge by now. Media Molecule isn't first or second party, but that doesn't change the fact that Sony owns the Little Big Planet franchise.

Well that is very good news, though it does not stop the possibility of them working on 3rd party games unfortunately.

If insomniac did own the IPs then they could always allow High Impact to work on them (especially as it was started by former insomniac employees)

Insomniac seem to take the view that focusing on one platform allows them to be cost efficient (only one set of tools/tech to understand) and only one platform to develop their engine on.

Given the number of titles they've squeezed out and the accumulated sales they've seen so far its hard to fault their choice.

I believe they are financially supported by Sony to a degree and certainly they've recieved and given an abundance of technical aids and assitance to and from many of Sony's in house studio, you could almost call them a defacto second party.

Insomniac prefer to remain indepedent, this is probably one of the biggest factor in Sony not acquiring them as Sony have shown in the past that they have no issue swallowing larger studios.

it's probably best to have a good mix of the two