Looks like GIGABYTE wanted to get their new HD 5800s out on the net a little early as we have an official product launch announcement from them in our inbox.
The new cards from GBT will be the GV-R587D-1GD-B and the GV-R585D-1GD-B. The names are a little odd, but after you take a closer look they sort of make sense. The R587D will be a 5870 etc. It is a very goofy phonetic teaser there, but all that aside the two cards will have support for up to three monitors including a display port out.
Each will have 1GB of DDR5 memory; the R587D will have 1600 stream processors while the R585D will only have 1440. Although not specifically stated you can expect to see these in stores shortly after the 23rd.