Well I don't know where your friend gets his information from so it's difficult to answer his skepticism but I used to work as a physicist for the UK Atomic Energy Authority on Nuclear Fusion Experiments at Culham next door to JET.
Jet was the first Tokamak ( a type of Fusion reactor) to achieve fusion. It took more energy than it released - this was a consequence of the design and not a failure.
The next generation machine is ITER (
http://www.iter.org ) currently being build at Cardace in France.
This will have the capabilty to generate more energy than it takes. but will not be a comercial generating site.
That will be DEMO probably in Japan (as they let the French have ITER)
A lot of the physics is sorted now. Iter will address a lot of the engineering challenges like how you divert plasma, how you maintain the reactor vessel etc.
If people continue to fund it properly ( and it's not that expensive ) there is absolutely no reason why it should not be commercially viable.
Quite a lot of the "It'll never happen" comes from some rather early enthusiasm in the 50s with claims like "Power too cheap to meter" from people who really didn't understand the difficulties - or did and knew that if you promissed results 70 years away they'd not get funding.
This is just one arm of fusion (Tokamaks) Laser systems are gaining ground but are still some way away. There are also "Pinch" systems too but currently Tokamaks lead the pack.
Check out the Iter site for a lot more detail