I think the most important feature that a business hotel should possess is strategic location. People engaged in business treat time lost as money lost; hence, it is critical that for a business hotel to be strategically located such that heavy traffic will be avoided without compromising the accessibility. Since most communication, deals, and discussions are done online, it is also critical to have in-room WiFi with reliable signal. Relative to this, work-desks are definitely one of the must-haves.
After long days of work, people may need to want to relax, and this calls for amenities such as gyms. Foreign travelers might give this aspect more importance specifically in trying to cut down the jetlag.
These are just some of the things that makes a business hotel a "great" hotel. Some other considerations may include having concierge, wide communal spaces, etc.