Showtime's Matt Blank kicked off the festivities on Day Two of the Television Critics Association Summer Press Tour by offering a look at what's coming up for their slate of original programming over the next six months or so. "Showtime continues to thrive in every part of our business," said Blank. "We received more 2010 Emmy nominations for our original series than any other premium cable network." Here are some highlights from the very brief session, during which Blank acknowledged the behind-the-scenes changes going on at the pay cabler, where Robert Greenblatt has stepped down and will be succeeded by David Nevins. Weeds comes back in August. Guest stars this season will include Richard Dreyfus, Alanis Morrissette, Mark-Paul Gosselaar, Linda Hamilton, and Peter Stomare. The Big C , which launches on August 16th as well, will feature Idris Elba, Cynthia Nixon, and Liam Neeson, whose participation was announced earlier this week. Dexter 's latest sea