how many lamps are there  

Two
One floor lamp and one ceiling fixture. The area is pretty small though.

You can't have too many lamps (or dimmers).
At the moment, we have two hooded metal floor lamps (one over each easy chair, for reading), plus, for ambience: a white-globed lollipop floor lamp; a sort of Noguchi-knockoff paper lantern on a shelf; the Objecto Eclipse on a side table, and a Panton-like silver-ball pendant over the stairs. Also a faint sort of cove light effect emanating from rope-light concealed behind top row of books on wall-spanning bookshelf. Room measures about 14 x 21 feet. Felt vindicated when cinematographer friend walked in, nodded, and said, "Ahh, numerous low-level light sources."

Three Aalto ceiling...
Three ceiling fixtures (aalto), two standard lamps, two table lamps, 1 desk lamp.
Also just counted a discraceful 18 lamps of various types in my (12' square & cluttered) office , of which probably only two or three actually have either plugs on them or bulbs in them...I think I have a problem.

Two
One ambient lamp in the corner next to the couch. One anglepoise next to the Eames.

too many to
I am with Geo H and the others.
I have many lamps and difffused-dimmed low level light sources, as well as brighter uplight washes for walls and the ceiling. A quick guess is over a dozen different sources of light, with half of them used most evenings.
Despite all the lighting I like them really low especially when listening to music in the evening. This always prompts my wife to comment on how dark it is when she enters the room. I suppose that compared to the TV and reading lamps in the other rooms it is dark by comparision. Viva la difference.

I used to use very many. Now...
I used to use very many. Now I am thinking a more minimal approach. Whenever I would have several low lights on, it just seems a little showy. A little too much mood when guests are over, like I am trying too hard. And also, I feel guilty for the amount of electricity wasted on achieving a feeling.
I am going with one floor lamp, the two built in sconces, and the overhead cans for now. So basically just one stand alone lamp for reading. Maybe I should get one with three intensity variations for mood .... or do they make bulbs that do that?

I've got a light "fetish".
I have four.
On the sofa side table, I got a "Tabla", design by Barbaglia & the great Colombo. I recently saw it advertized for twice what I paid for on www.lushpad.com.
On the other side of my sofa you will find a copy (me bad) of a "Moon Visor", designed by Verner Panton. A floor model, it takes the place of a ceiling mount fixture for I have solid cement up there.
My stereo system is lighted by a "Hedi", design by Isao Hosoe. I came across it at a thrift store for about $10-, what a find.
My computer desk is the home for a cheap discount store unit, no designer and from Chinese origin. It is well built and very functional.