Yes. It's real. Rev 18 was Waninkoko's biggest update to his cIOS as we redid almost all of the code. Waninkoko has even begun working on rev20 already. A key thing worth mentioning about the new revisions is that you can choose which iOS to use for the base from iOS37, 38, 57, 60 and 70.
Base WADs Possible Uses:
IOS37-64-v3869.wad -> Support for games with instruments (Rockband/GH/etc.)
IOS38-64-v3867.wad -> Widely known/supported/stable base
IOS57-64-v5661.wad -> First with updated modules "OHCI0 USB USB_HID USB_HUB USB_MSC USB_VEN ETH"
IOS60-64-v6174.wad -> Better network code / The Conduit (?)
IOS70-64-v6687.wad -> SD/SDHC speed/wifi improvements (?)
Check out all the info here: