If you dont like the system (everyting is stat/level based) in RPGs, you will not like MMOs. But the game experience itself is completely different. Depending on the one you choose, it looks like you'll want to join WOW due to your friend, the time commitment needed varies. WoW is pretty easy as far as leveling up and getting to the top, or so I have heard from dozens of people.
A typical routine in Lineage 2 (the MMO I used to play) went like this
>Go out to your favotite huntspot and grind for experience/cash (you'll do this about 75% of the time and it is more boring than just about anything). You chat with nearby player to help alleviate the monotony
>Every once in a while, anywhere from 2-5 hours, make a run to town to check out eqipment for sale, buy supplies, ect
>Every once in a while, depending upon your peronality, you'll try to get a party together and have soem actual fun. After about 20 min of getting it together, the group decides that the area they are in is too easy for their number. So, 20 min later, you arrive at a harder spot that you alone can't solo in, so after about 1 to 2 hours, the party breaks upa nd you have a 20 min walk back to where you can actually hunt
>Every 3-5 weeks, you spend an entire day trying to sell your weapon/armor for a decent price so you can buy a better set/weapon from soemone. But you have to be careful, or you ight not have enough to buy a new whater you just sold. If that's the case, you are screwed for as much as a week untill you get luck and find someone selling what you want.
>Once or twice a week, you go explore a new area, possibly get into a party, and have the best time of your life.
I know that doen't sound like a pretty picture, but that's how a I had to play to keep up with my clanmates. If you dont join a clan tho, you can take more time to smell the roses, but will miss out on the comraship, the large scale world politics, clan wars, castle seiges (in Lineage, at least), ect.
The bright point for those that can't become totally immersed in the sheer beauty and fantastic atmosphere of the virtual world (I was for the first week, then it sorta wore off) is the endgame, when you are so rich and powerful you can just take it easy, help some new plaers, and generally relish in your accomplichment. I think WOW will demand about 6 weeks of solid (20+ hours weekly) playtime to get to the top. Lineage would take over 8 or 9. With a freind to help you, you'll progress pretty fast during the early levels, and will havv a lot more fun htroughout than I did. Also note that my experiences and routines are, as I have said, based of Lineage 2, which arguably has the hardest grind in any of the big MMOs today.
I would devote a day to going over to your friend's house and playing on of his alternate characters or starting one of your own on his account (if WOW lets you do that). That's the only real way to tell if you'll like it.