I went through Nepal last month. It's as safe as anywhere else in the region. There are regular Maoist strike days when everyone is off the road so if you have time to sit tight on those days it would be best. I needed to hurry on so biked 300km on a strike day. Saw only two army vehicles moving all day. I wouldn't recommend it, nor want to do it again, but canvassing locals before departure produced a small majority vote that I'd be safe as a tourist.
The Maoists don't seem interested in picking on tourists (other than for a financial contribution when treking) so you should be fine. The Nepalese are friendly, helpful, people so try not to be too put off by alarmist news stories.