Kenobi, he's faster, vastly more skilled, and the more cunning of the two. Wyyrlok has powerful Force lightning, but I'm not convinced that Kenobi couldn't block it with hi saber in a similar fashion to AotC, and Wyyrlok's TK feats are inferior to Obi-Wan's.
If Wyyrlok gets the chance to cast his illusions at some point in the fight, he has a good chance considering his illusions are powerful enough to physically harm his opponents, but it isn't a n entirely game-changing position. Not sure how Kenobi would fare against a memory walk, though.
I see no reason to think Kenobi could block lightning powerful enough to shatter stone pillars, at least not easily at all.
Also, personally I don't see Kenobi winning with lightsabers. He's not aggressive enough to overwhelm someone who'd prefer to disengage and attack with the Force.
Vastly more skilled? Wyyrlok was able to engage Krayt in a duel on good terms. Kenobi greatly respected and was worried about A'Sharad Hett's skill and while he beat Hett decisively, it was not without being bloodied.
Yes. Two skilled non-aggressive lightsaber fighters is going to take some time. Force shall decide.
__________________ "Happiness is a lie. Life is horror. The light is always dying all across the universe. The last star will flicker out someday, when it does, all that remains is shadow. And I will be its king!"'-Amahl Farouk