You're on the right track. As to what will differentiate them, you'll find out in time.

I gather they are being called as 'highly maneuverable' ships.

That made me think that maybe the corvettes, instead of using the fly-to-the-front-of-the-enemy-and-stops-like-a-sitting-duck, it could use the fighter-like fly-by behaviour.

That would be an interesting cross-breed between frigates and fighters, and the smaller corvette ships could give a hard time for the bigger ships to target them, depending on how targeting works.

Make them phased out vessels.They would perform the function of stealth ships.Low damage,good sabotage buildings,starbases and Titan class ships.

Corvettes really sound a lot like how scouts were used in 1.18.  Certainly a 2 command unit would satisfy the "smaller than (most) frigates, bigger than strike craft" status.

The capital escort Idea was much interesting wouldn't you say?

*hears loud chicken sound in the background*

THE HOLY PROPHETS OF STARDOCK HAVE SPOKEN!

*bows repeatedly*

Seriously though, that's awesome. But the waiting! It's so difficult.

In homeworld corvettes were larger than fighters and could still dock on carriers. I would say like fighters they will operate in squadrons.

Would be cool if the new corvettes would be like a faster version of the existing light frigs, and frigates in general would become a little bigger. More weapons, hulls and fleet supply.

A frigate class ship that just sits there in battle should have more guns imo. 

Hound, I really like that idea.  If you could choose a squad of corvettes as an option instead of strike craft that would allow for some interesting customizations of carrier cruisers, cap ships, starbases, and hangers.  Maybe cost 2 strike craft slots for 1 corvette option.  I'd love to see this implemented.

       Did I read somewhere that corvettes might have fighter style movement? I like the idea that they could be docked in a carrier. Maybe we finally have a use for the dock/undock button............

The developers hinted that strikecraft-styled movement, a la their role in Homeworld, was 'on the right track' for the new corvette ships.  Well, maybe not precisely... But still, given their role in Homeworld, and the ties between Homeworld and Sins, I think you might see strikecraft movement from them.  It should be the new preferred view for watching big fights on replays of recorded games, with the awesome battle music playing in the background.  

As for the dock button, I use it sometimes when I have fighters around and the enemy has flak.  No sense getting them all gutted in seconds.  Bombers can usually hold their own and be left out at all times. 

You also have to wonder what corvettes will counter, if anything.  bombers and lrm's are what most people talk about right now.  if they can counter lrm's, that could take the pressure off of lf's to go after enemy carriers (and let capital ships live longer) and free up the fighters to concentrate on the bombers.

Their speed might enable them to close the distance with lrm's quickly and might not be targetable by them if they move like strikecraft.  but then, what counters corvettes?  flak? lf (to give them more to do)?

However, if they are launched by Titans the way caps and carriers launch fighters, then that could be a whole different can of worms.

To tell truth, we really don't know enough about corvettes to say what they would counter or what kind of attributes they have.

In Wing Commander I and II, Corvettes were small, fast ships that operated as something akin to a super-heavy bomber. They Were as fast as the bombers, but packed more firepower, and were excellent at anti-bomber, anti-freighter (trade ships), and anti-light-cruiser (Support/LRM, anyone?) - and they were vulnerable to heavy cruisers, cap-ships, and fighter-craft. Frequently deployed in pairs or trios.

Which sounds sort of like a light frigate that's decent at killing LRMs and moves faster

Edit: bolded for giggles.

I will guess/vote for corvettes to move in combat like fighters, instead of standing still, have special abilities like frigates, and have shields, but no jump drives, so they must be docked on carriers to go to another gravwell.