I do get that question when I am doing Home Staging Consultations. The good news is the person asking it is up on the current trends, the bad news is usually they are trying to justify their decision to not remove their wallpaper before putting their home on the market.
A couple things on wallpaper:
1) Yes it is back in style but I say that with caution as it does depend a bit on the region of the country you live. Some areas the trend isn't there yet or you only see it occasionally.
2) Then there is the issue of style of wallpaper, the pattern, the area of the home where it is located and the amount of wallpaper. The trend now is wallpaper on perhaps one accent wall, in the foyer or the back wall of bookshelves. It is not an entire large living room or bedroom.
The current style you see is usually a large pattern, bold and many times metallic. 
Not small floral prints and not busy patterns, so let's just say not your Grandmother's or even Mother's wallpaper.
When I work with clients who are not moving and are interested in using wallpaper I still caution them.
If they don't have any plans of moving for ten or more years then I say go for it. If they may move in a 1-5 they need to know their time and cost may be short lived. Either way that wallpaper may need to come down when they go to sell their home.
Here's the deal with wallpaper:
1) People either love it or hate it.
2) If they love it but hate your pattern they basically still hate it and see it as a chore to remove it.
It is a HUGE negative in the eyes of buyers. My advice to sellers is to always remove it. I do have a few exceptions but they are few.
So if you are looking for my expert decision on wallpaper when selling, remove it.
Shar Sitter, owner Rooms With Style Home Staging and Redesign Minneapolis MN.
CHSE and APSD Home Stager Pro Trainer
www.RoomsWithStyle.com
952-567-1124
