Looks mostly like a fail to me. Instead of simply modernizing the original and making it as a standalone movie, they are sending "Rusty" (who looks nothing like Anthony Michael Hall) on his own family vacation. Christina Applegate plays his wife.
The new version seems to be a combination of overt grossout humor (the original used very little of that, and was subtle when they did) and obnoxious nods to the original, almost to the level of parody.
The grown up "Rusty" is nothing like the teenage version, and is far more naive and white-bread than any of the Rustys we saw in the various Vacation movies.
John Hughes would likely not approve.
Of course, the original trailer from 1983 didn't look all that funny, and then the movie itself was great:
Loved the title sequence with real postcards from vacation spots around America: