The Eagles hosted a media session featuring some of their coaches earlier this week. Les Bowen of the Daily News has a really nice summary of what took place. And yes, defensive coordinator Sean McDermott admitted that he might use a 3-4 scheme at times. The 4-3 will still be the Eagles' base defense, but it would be interesting to see it change from time to time.
"The prime information there was that McDermott acknowledged what we've all been speculating on -- as he tries to find ways to use all his new personnel, he is thinking of doing more with 3-4 looks," writes Bowen. "The Eagles' base defense will remain, but they've shown 3-4 here and there in the past, and that tendency very well might increase. The biggest obstacle would seem to be the lack of a true 3-4-style, monster nose tackle. McDermott said he thought Brodrick Bunkley could fill the bill, and he noted that Antonio Dixon is "320 and rising."
The Eagles don't have the prototypical linebackers for a 3-4, but there's no reason they can't have some success with the scheme if used in spots.