Well I can give you the report how it was with our group.
We first tried it over Teamspeak, I wasnt doing the DM in that try, but was just a player.
We had 2 americans and 1 canadian who spoke good accent free easy understandable english. While my english is pretty good I have a pretty strong eastern european accent, then we also had an australian who had a very distinct way of talking so it took some time to get used to it. It had problems here and there, but the main problem was. One of the guys had a very soft whispery voice and another one was very shy and didnt talk much. It kinda sucks for roleplaying purposes as they only could roleplay shy characters. It isnt really viable to roleplay a womanizer bard when you're not talking much.
After the first game we decided to try out doing it over IRC. I was doing the DungeonMaster.
We used some GURPS rules and I wrote a basic science fiction setting, it wasnt anything special. A corporation hired a group of people to infiltrate and sabotage another one and I made the quests based around it.
In the IRC we used OOC: (out of character) everytime we were talking about anything not related to the game. Banter between us, random smalltalk and such stuff. We really had an awesome mood going on like in that video, while we were rolling and doing our quest we were talking about many things.
Most of the time they talked in character, like one guy roleplayed an ace hacker who was afraid of women. Anytime he was talking to a questnpc or partymember that was female he'd stutter. While you dont have intonation you have plenty of ways to characterize your speech. Like that guy was always writing "H-h-hello g-g-ood to m-m-meet you" or I had a quest NPC say someting along the lines "A shady merchant approached your group, he was talking in a sneery voice and was belittling you when he asked you if you want to buy some weapons"
And you can have your character yell out his attacks.
I could announce that a group of rats approaches the group. You could then write something along the lines of "Steve the warrior jumped at the enemies and yelled LIGHTNING FLASH" and then you roll for your attack.
Or we could use the IRC solely for incharacter/gamerelated stuff and use teamspeak for out of character talking.
I'm also a very fast typer which makes it a bit easy for me to dungeonmaster in IRC.
If you're interested in this and have some people interested we can do something.
I'll be on holiday from august 3rd - august 12th, I could use that time to come up with a setting and a story, could be fantasy or sci-fi.
Fantasy is a very good/easy first time p&p rpg as it is easier to write a setting/roleplay in and there's very good beginner friendly fantasy rulesets. A science fiction or post-apocalypse setting would be a lil bit more demanding in the rules section depending on what you want to have, cybernetics, vehicles, drugs, etc etc.