Many pastelists consider their pieces to be paintings. Here at American Artist, we have tried to steer clear of the debate on whether pastel is a drawing medium or a painting medium, although when put against the wall and poked in the chest, we'll call them paintings. (Don't mess with pastelists!)
There are interesting arguments from both sides of the issue. On one hand, for the painting argument, pastel is pure pigment. Vibrant color--not something you associate with drawings, colored pencil pieces notwithstanding. And a pastelist usually thinks in terms of planes instead of lines. Edges in drawing are lines, while the edges in pastels are simply the place where two colors meet. Additionally, glazing of sorts often occurs in a pastel work, in which one color shows through the light application of another color to suggest a third color, just as in oil painting.
On the other hand, paint is generally understood to be liquid--or at least to be in a liquid form when it is applied. Also, paint is usually applied with a brush. And some people's definition of drawing centers on the very immediate and tactile scenario of putting marks on a surface with your hand. For them, a paintbrush puts too much distance between the surface and the artist's hand.
Drawing magazine features pastels now and again, but most of our pastel articles stay in American Artist.
I don't really think it matters how pastel is categorized, and I don't think that pastel is insulted either way, but exploring this topic is perhaps useful because it makes one consider the properties of the medium and how to use it whether you are sketching or making more formal works. Often, the more the nature of the medium is taken into account, the more successful the resulting piece is. Consider watercolor pieces that capitalize on that medium's fluidity, or charcoal pieces that make good use of that material's dark darks.
So, what do you think? Does the distinction matter? And if it does, is pastel a painting medium or a drawing medium?

Christmas Field
by Liz Haywood-Sullivan, 2003, pastel drawing on black paper,
24 x 50. Private collection.
Note how the sky is drawn in with white marks that almost suggests hatching. The sprigs of grass and the branches of the bushes and trees are linear. So is this a drawing?

Attitude
by Patricia A. Hannaway, 2006, pastel drawing on toned paper,
21 x 12. All artwork this article collection the artist.
Is this a gesture drawing made with color, or simply a painting quickly suggested with pastel pigment.

Six Friends at Dieppe
by Edgar Degas, 1885, pastel drawing, 45¼ x 28. Collection the Museum of Art, Rhode Island School of Design, Providence, Rhode Island.
Degas seemed to have drawn outlines and then added local color, with little modeling.

Silver Cluster
by Janet Monafo, 2007, pastel drawing, 50 x 38. Private collection.
This looks painterly, but it's tightness could have been executed in colored pencil, and it's nearly monochromatic feel suggests graphite. You could also convince me that it's an oil painting based on this reproduction.

Roman Bridge,
Le Quercy
by Judith Carducci, 2006, pastel drawing, 12 x 9. Private collection.
This, on the other hand, seems far from being a drawing.