If I were the making the decisions, I might actually consider sending Veal back to the Cubs. Veal has shown no signs of being able to pitch effectively at the major league level any time soon. He's walked ten batters in 6.3 innings so far this year for the Pirates, and he walked twelve batters in 12.7 innings in his "rehab" stint at Indianapolis (although he did allow just four hits). He has good stuff, but he's 24, and it'll be quite a while before the Pirates can send him back to the minors to get the seasoning he obviously needs. Taking Veal in the Rule 5 was a high-risk, high-reward gamble on a pitcher with serious control problems. What possible indication has there been that the Pirates' gamble might be successful?
It's true that the Pirates shouldn't be quick to give up young talent. But Veal was a huge question mark to begin with, and he's not particularly young anymore. And this year, he's pitched less than 20 innings. If he's ever going to be a successful pitcher, what the Pirates are doing to him this year is not likely to help.
If returning Veal isn't a possibility, I'd probably demote Steven Jackson, who's been a mess of walks and runs (ten overall, including three unearned, in 16.3 innings). Matt Capps and John Grabow aren't going to the minors. Jesse Chavez has been fine, Evan Meek has walked more batters than he's struck out but has generally kept runs off the board, and Jeff Karstens is perfectly functional, I guess, as a mopup guy. That leaves Joel Hanrahan, who I really think will produce if given time--his stuff is good and he continues to post good ratios.
As for Doumit: the Post-Gazette reports that the Bucs might consider keeping both Jason Jaramillo and Robinzon Diaz around and using Diaz in a kind of roving role. Perhaps they'll get him some at bats at third or first, which he played sparingly in the minors. I think this is very probably what they'll end up doing--Steve Pearce has all of two at bats since June 24, so plainly the Pirates think he's expendable. Jeff Salazar could also be demoted.
Here's a crazy idea, though--send Jaramillo down and install him at Indianapolis' starting catcher, then market either him or Doumit to teams who might want an upgrade at catcher. Diaz has shown he can be a perfectly good backup, but probably nothing more; Jaramillo might well be better. Jaramillo has hit .262 AVG / .335 OBP / .400 SLG so far this year while playing good defense, which probably makes him an above average starting catcher. There are several contending teams, such as the Brewers, Tigers and Rays, who have gotten very little from their catchers, so Jaramillo might well generate interest, particularly if he tears the cover off the ball at Indianapolis.