Check out a new website edited by Richard Bull – ManasluCircuittrek.com
It’s about 170km hiked over 2-3 weeks.
… the Manaslu Circuit Trek takes you from just 700m altitudes at Arughat (or Gorkha Bazar) up to 5160m on the pass – a tremendous range of altitudes, temperatures and micro-climates. …
Manaslu circuit is now a tea-house trek. Camping is not required unless you go off the beaten track. Here is a rough outline of the route with some information about where the tea-houses and lodges are. …
Robin Boustead (Great Himalayan Trail pioneer) says:
“Many would argue that the Manaslu Circuit trail is the best general trek in the country, with colourful cultures and dramatic valleys against a backdrop of classic Himalayan peaks.”
Richard has mixed feelings about promoting this excellent alternative to Annapurna and Everest Base Camp. But I feel progress is inevitable. Best it be managed for the maximum benefit of the local peoples.
Andy Bryant posted a terrific trip report.
besthike.com 
You should go and check it out!
(How can it take 2-3 weeks to walk 170km? That’s 5-10 mpd! Hope they’re not trying to pad the trip for more income.)
Was hoping to hike it before it will get to touristic. Too late.