So, today I installed Lion twice on my computer. First time just to test it on an older hard disk and the second time I replaced my Snow Leopard. Yet, there are two issues I get:
About My Mac says something about "MacBook Air (original)" which is probably just a cosmetic issue and wake up from sleep doesn't work. Since I have some older Kexts in my Extra/Extensions folder I might try some newer ones to get wake up from sleep working.
As I posted above, I have the same issue with the "MacBook Air" thing, yet, my Lion tells me the correct CPU. Just google for SMcputype and put the correct lines into your smbios.plist.
//EDIT: The computer justs need a little action (mouse click) so the black screen disappears and it wakes up from sleep.