Special means that this isnt the planned yearly meeting.

these meetings are usualy done for several reasons.
When the company is losing marketshare or has product delays they make these meetings to ensure the stockholders that stuff isnt going like planned but that it isnt going as bad as the media says, so simply to keep confidence up.

another reason todo these kind of meetings is to tell the shareholders about a big change for wich they need the stockholders permission.
Like AMD is gonna ask them permission to sell AMD to another party.

lets hope they are gonna anounce plans to be taken over or fuse with IBM.