Even though ABC's aggressive move to topple The Today Show appears to be working so far, it has backfired a bit.

According to sources, anchor Robin Roberts and Elizabeth Vargas are furious over the network's decision to put Katie Couric in the GMA co-anchor role next week while Roberts is on vacation. Roberts is agitated by the high-profile substitution in her absence and has never been impressed with Couric's pluck or perceived star-power. Vargas has more justifiable gripe since she's been under the assumption that as part of ABC/Disney's plan to increase her role and visibility she was first choice to slide into the co-anchor seat when Roberts is away.

Sources also say that ABC exec Ben Sherwood's hatred of NBC may have to be reined in until the tensions caused by Couric's presence subside.

[Images via Getty/AP]