Been playing exploring my way round Second Life and currently our small team at work has been showing an interest. It seems that we will all end up with an account at some point, even if it's just to see what the fuss is about.
Jisc have just finished an online conference - Innovating E-Learning 2007 at which there was a session in and about SL. We looked at barriers to use and one that came up (and has elsewhere) is the time needed to learn how to manipulate yourself in world - move, chat, navigate, find places, view and did I mention move ... One of my colleagues fell into some deep water and couldn't get back out! He had to reboot SL to save himself from a virtual drowning 
This may just seem like the ravings of someone too old to be there in the first place but it points up an important fact about using technology in or for learning - if the technology gets in the way, the learning opportunities will be diminished (unless an understanding of the technology is the desired learning outcome or you want to introduce a cognitive load while learning about something else).
I don't think that SL is too hard to learn (I managed 
) but I think that one will have to carefully apply something such as Salmon's 5 stage model to getting people in-world and connected as a cohort before any other learning can happen.
Keywords: 5 stage model, jisconline2007, Salmon, second life, SL
