She may have had a large support group including her good friend Oprah, but it seems as if she got disappointing reviews from the press. US Weekly has gathered some quotes from the various newspapers. I thought these 2 were the most interesting:

• Well, she gives it the old college try — and that is all she appears capable of. As if marooned on an unfamiliar shore, Julia Roberts staggers hesitantly through Three Days of Rain. . .
  Mostly Cloudy: Julia Roberts in ‘Rain’ [WaPo]
• O.K., if you must know, she’s stiff with self-consciousness (especially in the first act), only glancingly acquainted with the two characters she plays and so deeply, disturbingly beautiful that you don’t want to let her out of your sight.
  Enough Said About ‘Three Days of Rain.’ Let’s Talk Julia Roberts! [NYT]

As for her famous friends who came to support her - People reports Oprah, Susan Sarandon, Tim Robbins, James Gandolfini, Diane Sawyer, Dave Matthews, Rosie Perez, Marcia Gay Harden, James Lipton, and New York City Mayor Michael Bloomberg. Hmm, no mention of hubby Danny being there but I'm sure it was just overlooked. Somehow I also don't think the reviews will hurt tickets sales.