Well, this week has been the first week of ISA AIM trading.
AIM-All Share Index is up 2% for the week. It's been in a strong uptrend since July, so not sure how much effect the ISA trading has had.
However, I think in the coming weeks it will continue to rise as more people stick AIM in their ISA's, as this week not all brokers allowed the full list of AIM shares in ISAs.