If Romney won; 2012 senate elections

[Politician]

Key races:
Arizona: Jeff Flake beats Rich Carmona, 51-44.
Connecticut: Chris Murphy beats Linda McMahon, 50-47.
Indiana: Richard Lugar is renominated, and beats Joe Donnelly 55-43.
Maine: Snowe retires, Angus King wins 48-32.
Massachusetts: Scott Brown beats Elizabeth Warren by half a point and after a recount.
Missouri: Claire McCaskill beats Todd Akin 51-42.
Montana: Denny Rehberg takes out Jon Tester, 49-45.
Nevada: Dean Heller beats Shelley Berkley, 49-43.
New Mexico: Heather Wilson beats Martin Heinrich, 49-48.
North Dakota: Rick Berg beats Heidi Heitkamp 54-46.
Ohio: Josh Mandel takes out Sherrod Brown 49-47.
Pennsylvania: Bob Casey beats Tom Smith 49-47.
Virginia: George Allen beats Tim Kaine by half a point.
Wisconsin: Tommy Thompson beats Tammy Baldwin after multiple rounds of recounts.

[NewYorkExpress]

Key races:
Arizona: Jeff Flake beats Rich Carmona, 51-44.
Connecticut: Chris Murphy beats Linda McMahon, 50-47.
Indiana: Richard Lugar is renominated, and beats Joe Donnelly 55-43.
Maine: Snowe retires, Angus King wins 48-32.
Massachusetts: Scott Brown beats Elizabeth Warren by half a point and after a recount.
Missouri: Claire McCaskill beats Todd Akin 51-42.
Montana: Denny Rehberg takes out Jon Tester, 49-45.
Nevada: Dean Heller beats Shelley Berkley, 49-43.
New Mexico: Heather Wilson beats Martin Heinrich, 49-48.
North Dakota: Rick Berg beats Heidi Heitkamp 54-46.
Ohio: Josh Mandel takes out Sherrod Brown 49-47.
Pennsylvania: Bob Casey beats Tom Smith 49-47.
Virginia: George Allen beats Tim Kaine by half a point.
Wisconsin: Tommy Thompson beats Tammy Baldwin after multiple rounds of recounts.

I don't see Warren losing, and I think that Casey and Murphy both lose.

[Lechasseur]

Key races:
Arizona: Jeff Flake beats Rich Carmona, 51-44.
Connecticut: Chris Murphy beats Linda McMahon, 50-47.
Indiana: Richard Lugar is renominated, and beats Joe Donnelly 55-43.
Maine: Snowe retires, Angus King wins 48-32.
Massachusetts: Scott Brown beats Elizabeth Warren by half a point and after a recount.
Missouri: Claire McCaskill beats Todd Akin 51-42.
Montana: Denny Rehberg takes out Jon Tester, 49-45.
Nevada: Dean Heller beats Shelley Berkley, 49-43.
New Mexico: Heather Wilson beats Martin Heinrich, 49-48.
North Dakota: Rick Berg beats Heidi Heitkamp 54-46.
Ohio: Josh Mandel takes out Sherrod Brown 49-47.
Pennsylvania: Bob Casey beats Tom Smith 49-47.
Virginia: George Allen beats Tim Kaine by half a point.
Wisconsin: Tommy Thompson beats Tammy Baldwin after multiple rounds of recounts.

I think the GOP still loses the Senate seats in Indiana (as Lugar still loses renomination) and Massachusetts (it would need to be an absolute GOP landslide for Warren to lose that race), then I think the Democrats hold on to the Senate seats in North Dakota and Montana, as they are states where people tend to vote for the candidate rather than the party, and besides I think both states already went pretty strongly GOP in 2012 so I don't think there would be that much room for improvement.

But I agree that the GOP pick up the Senate seats in Virginia, Ohio, Wisconsin and just maybe New Mexico along with Nebraska that the GOP picked up IRL, which would give the GOP 48 or 49 seats in the Senate rather than the 45 they held after the 2012 election IRL.