I haven't seen either the Logic 102 for Logic7 or Logic 105:Logic's Environment Explored.
Judging from the logic 102 EXS24 Explored for Logic 8 and the difference in both tutorials TOC, the are very similar. However, the Logic 8 version has been re-designed and re-done with Logic 8 in mind.
RE: Logic 105, yes, I think it is still very applicable for Logic 8 users. Not much has changed in the Environment from Logic 7 to 8.
There are a couple of chapters that may not be applicable in "Section 2: Tricks with Objects". Logic 8 makes it easier to create all tracks you need without necessarily needing to go to the Environment. That said, I still use the Environment when creating customised Mixer window views etc....
BTW you can also find lots of great designProVideo tutorials ;-)
Hope that helps,