Good news indeed.
What I have not seen lately from is any news about raid arrays. Arca Noae had said in the past that new raid devices might be supported. I for one would like to see the LSI MegaRaid supported. They work well with SSD devices.
I have need of a PCI SATA adapter, so I got a Startech 4 port SATA RAID controller (there is an equivalent for PCIe). The first thing I did, was make sure that it would run a 1 TB disk in an old machine as a normal IDE disk. Yes, it does, but it took me about 2 days to fill it up.

I have a 1TB disk, but the docs say the hardware can support any size disk, although there is a 2 TB limit for disks in a raid array. Apparently, OS/2 also has a 2 TB limit.
Having seen this thread, I decided to try RAID, since the docs indicate that it is really done in the BIOS. I took an old 500 GB disk, and paired it with a new 1 TB disk. The RAID array is, of course, 500 GB (but it is only a test). I set it up as a RAID1 setup (I can't see any advantage to using any of the other options, although a raid 1+spare could be good), and it started to do the rebuild. Then, I booted eCS 2.2 b2, with fixes, and it "sees" the disk. Actually MiniLVM "sees" both disks and complains that the second disk has a corrupted partition table (the boot drive is still on an IDE disk). The 500 GB disk had an NTFS volume on it, so I used LVM to delete that, and put a new LVM bootable volume on it. I carefully ignored the second drive and saved the configuration. It appears to have done that, with no complaints, so I formatted it as JFS and I proceeded to copy data to the paired drive, which appears to work okay (the rebuild is still going on, in the background, apparently with no OS support, and for no good reason at this time, but that seems to be what it does). Another anomaly is that the SATA drives come before the IDE drives (according to MiniLVM). That doesn't seem to cause a problem.
There are windows, and Linux, "drivers". From what I can tell by reading the docs, all that does is give the user a way to see what is going on with the raid while the system is running, and it will e-mail somebody with information (which is configurable - I would assume that a disk failure would be the most important bit of information). It would seem that a user doesn't need that, but they should reboot occasionally to see what the raid has to say since there seems to be no other way to know if something goes bad, when the driver is not active.
If you are looking for a performance boost, forget it. This thing runs at IDE speeds. The PCIe version should run faster. I don't see any indication that it will run AHCI, which should not be a problem.