Marios Karagiannis, the developer of MonsterUp for Windows Phone, has noticed that a couple of yet unannounced Nokia Windows Phones as well as Windows Phone 8 builds have played his game. As a matter of fact, it looks like Nokia has at least 3 unknown Windows Phones under development which indentified themselves as the "Nokia SGH-i917R", "Nokia Fluid", "Nokia Dogphone" and the "Nokia Phi". However, it should be noted that the "SGH-I" naming scheme is typically used by Samsung for its GSM/UMTS flagship devices. Nevertheless, it looks like also Microsoft is doing some real progress with Windows Phone 8, which still needs to be officially announced, since Karagiannis also found a lot different Windows Phone 8 version number in his logs.

The Windows Phone 8 versions in question are "8.0.9698.0", "8.0.9697.0", "8.0.9696.0", "8.0.10101.0", "8.0.9691.0" "8.0.9695.0" and "8.0.9699.0".
It's clear that, if Windows Phone 8 will be announced this summer/fall, there are floating a couple of internal Windows Phone 8 test-builds around but it's really interesting to see Nokia's code-names for their expected upcoming Windows Phones; even if they say nothing to us today.
Cheers ~ Arne