A former coworker I know went to Walden for her FNP and she is doing very well, although I think she was somewhat of a perfect candidate for them. She currently works as an ER NP, a large chunk of her nursing background is in the ER, and she did a huge chunk of her clinicals in the ER that she currently works in. I'm not a fan of for profit schools with little oversite, but in certain circumstances where the student has solid experience and connections, I can see where they can be successful.
Academically, I can't say I'm very impressed with their program. The spouse of an Internal Medicine physician I work with is currently enrolled in Walden's FNP program, and as an older student, she really struggled with the online aspects of the program and would ask me for help. The assignments in her patho, pharm, and advanced assessment courses were pretty pathetic, and even with her poor writing skills (partially because English isn't her first language), she would get full credit every time. She also wasn't actually taught any skills to prepare her for her clinical rotations.
I'm actually a fan of online programs if they offer good on campus experiences and clinical oversite, but schools like Walden are out to make a quick buck, typically from students that had substandard GPA's for admission to more traditional programs.