As I have written, I don't like Skype. Then someone may ask: what do you think a perfect IM should be? I think there are two key points:
1. An Unique ID
People on line need an ID, in nowadays each website assigned an separate ID for each user. To a single user, in theory, using thousands websites, he/she needs to remember each different ID for each websites. Fortunately, in practice, many users are used to choose a unique ID, then using it everywhere. But this habit often conflict with the fact: it is hard to choose a real unique ID on net, and the ID preferred may be chosen by others on specified websites.
But wen do have an unique ID already: an email address! Why we can't use it as our other services, for example, IMs?
In fact, nowadays, more and more websites do use email address instead of assigning separate 'user name'. Why not so for IMs?
2. Communicate with people, but not with people using specified IM!
Current IMs all set walls for people not using same IM client. Yahoo messager users can't communicate with Skype users; Skype users can't talk with Gmail users ... IF AT&T set a rule that AT&T users could only call to another AT&T user, but could not to T-Mobile users or ... Do you think that is acceptable?
We need right to choose IM freely, and using any of IM to communicate with any of other IMs the receiver chosen. And here 'communicate' is not limited to text, but also audio, video and any future forms.
And the perfect way of going with IM
The email address is the only thing, needs to be written on contact cards, just like the old way of telephone number goes.
By the way, I also don't like fashion SNS logo: a name goes with tens of logos of SNS websites.
People with an email address could find the one on email, IMs, SNS websites ... And when they are communicating, the only thing need to consider is: To go with a talk, with a mail, with a photo, or with other type of contents, but not the software by which we could talk!