Yesterday's Second Life client update improved in-world instant messaging and presence. From the change log:  

• Added: a new Profile tab shows a web page of the profile owner's choice without launching a browser. (more than Skype)
• URLs in chat and IM are now clickable links. Supports http://, https://, secondlife:// (hmmm, wish skype: links were clickable in 2L)
• Log IMs and/or chat (hmmm. Are my Skype moods and presence logged?)
• Permit friends to see you online/on the map (Presence, availability and location. I'd like that, maybe let GPS or cellular tower codes update Skype via SMS/texting?)
• Conference IM multiple friends by multi-selecting in the Friends list (multichat! only one step to conference calls.)
• See who granted you permission to modify their objects in the Friends list. (this personalized presence is almost relationship brokering: who can see and do what with me when, where and in what ways.)
• Set whether you show as online in Search (Spreads your presence data, making people-search more actionable.)

2L's on a great trajectory: 

• it's matching features with the popular IM clients,
• expanding presence depth and accessibility, and 
• making it slightly easier to blend the outside world into the 2L experience.