Friends of mine did that in their @1870 home. They had a lovely little stained glass and leaded window and no where to put it, so they put it in the living room wall, where it glows in a little dark cubby of a corner off their dining room.

If you cut to the studs, usually not to hard.
Ending between studs gets a little harder.
For wood (or metal) lath expect some cracking and damage.
For gypsum lath careful cutting (use a rotozip) will produce a clean cut.

I,ve had great success with curtain-wall and i suggest you to use www.curtain-wall.com

First off, I say it's a wonderful idea - I did the same thing between a kitchen and dining room and have been very pleased - adds interest and practical benefits to both rooms.

Main thing I question is your width calculations. You initially said 2', but they you said between the studs, which is more likely about 14". I don't think 14" is wide enough for a window, so you'll probably have to "header up" one stud, especially if it's a load-bearing wall. It's still doable, and in my opinion, worthwhile, but there will be a little more framing involved and you may have to make the opening bigger to give yourself room to work.

As far as cutting in goes, I used a reciprocating saw held at a very hard angle to cut through the plaster first, then angled in to cut the (wood) lath. If you're cutting right next to a stud, cracking adjacent plaster should be less of a problem.

Psteenhoek's idea of using a circular saw with two blades sounds theoretically better, but the problem with plaster and high speed blades is dust, and lots of it. I prefer easing in a recip saw blade to cut the plaster, clean out the loose plaster, then get a new blade to cut the wood lath. It takes a bit of a touch with the recip saw, but is much less dusty than a circular saw cut (though still dusty enough!)

I had something like that done a long time ago, and loved the result. It was in the second story hallway of my 1867 "Carpenter" Victorian. I cut a large opening in a stair hall, opening it up to the staircase below.

It created a ton of dust and the contractor had quite a job patching the plaster, but the overall effect was wonderful. Tons of light, a much more open feeling.

Go for it!