It'll be interesting to see if they still can design and build a new ground-up airplane design. The last all-new design was the 787, initiated in 2003 and launched in 2009, and its design was fraught with problems. Before then was the 777 in the early 90s (pre-McDonnell takeover), and the 757/767 in the early 80s.
There's a phenomena that ofter occurs with large organizations where once their markets mature, everybody who can build a product end-to-end leaves or gets forced out, leaving only people with highly specialized maintenance skillsets. The former group has no work to do, after all, so why should the company keep them around? But then if the market ecosystem shifts, and a new product is necessary, they no longer have the capacity to build ground-up new products. All those people have left, and won't come anywhere near the company.
Steve Jobs spoke eloquently about this phenomena in an old interview: