Nope. The problem is that the TIFF exploit is closed in 1.1.2, thereforee, there is no "door" to come through to jailbreak with like in 1.1.1.
The OkToPrep basically holds a "door" open specifically after updating to 1.1.2 so that jailbreak is possible, but since it's not a exploit of safari, using the jailbreakme.com site will not work.
haha. i realized how dumb i was when i was trying to re-jailbreak my phone after i had jailbroken 1.1.1 and upgraded. I had gone to jailbreakme.com and done the whole shebang with the TIFF exploit on 1.1.1, and even installed oktoprep on it before i upgraded. Then, as soon as a method was availbale for a PPC, i read the directions fully, and downgraded to 1.1.1 even though i didn't have to. But, to kick my phone out of recovery mode, I had to have iNdependence installed. So, i did that, but it wouldn't work because i have iTunes 7.5... so out of frustration, i re-upgraded to 1.1.2.
i found the Apple mobiledevice support for iTunes 7.4, installed that with iNdepedence, and re-re-downgraded to 1.1.1 did oktoprep, and then re-re-upgraded to 1.1.2