Yes, your footage will be interlaced. Only the newer or high-end consumer cameras have progressive capabilities, and you have to specifically turn them on.
The easy way to check for interlaced footage is to play it in Windows Media Player (or something similar). Look for odd horizontal banding wherever there is movement. This is due to the two fields playing at once, so they look somewhat offset (which doesn't happen on a television, due to the different way the frames are processed).
When viewed on a monitor, an interlaced frame will look something like this (taken from an old hi8 camera):
This is due to both fields being shown at once. It'll be fine if played back on a TV. This is why you deinterlace films before putting them up on the internet, as you don't want those kind of artifacts.
However, deinterlacing reduces the quality, which you obviously don't want to do while still working on the film. This is why you split the fields instead. This is temporary and enables you to do special effects work without the interlacing causing problems with positioning. So the above shot once split into its two separate fields looks something like this:
Once you're finished, Chromanator will automatically recombine the fields, meaning that the effects will play normally on a TV screen and the footage will not have lost any quality.
A progressive clip, on the other hand, is just a normal full-frame image to begin with (taken from a Canon XM2):
So nothing needs to be done to progressive footage - well, other than ticking the progressive box in the new project settings.