iPhone OS4 details

Apple finally revealed multi-tasking feature in iPhone OS4, which is one of the demands from current iPhone users including me, of course. It will be releasing in summer, might expect right before iPhone HD is coming out in June, so pretty exciting for people thinking of switching to smart-phones, mobile market in Japan is gradually shifting by the way.
For details of iPhone OS4, not discussing here due to tons of translated resources out there already, pointing out what we will see might be better and interesting to express as my own point of view for getting rid of stress from everyday life.
Well, in the presentation, some hit my interest and curiosity, one of the reasons is that apple amazingly smart of finding the points where people love.
Besides multi-tasking, we knew this is what we have been waiting for but also were convinced of things we are worried.
For instance, memory while using multi-tasking, can be eating up performance and battery life when I see the solution, however Apple has ensured that it won't cause the problem, as long as using recent ones such as 3GS and 3rd gen iPod touch, sorry my iPhone 3G though. OS4 nicely delivers and helps our life easier.
Actually, the most interesting topic was iAd, this is much way beyond from what I
expected and it could be lifting up next level of online banners for
mobile definitely. Before this idea came up, he mentioned that current
mobile ads are very weak and not user friendly cuz it seems overwriting
contents, forcedly navigate to contents related to the banners you
clicked.
this is surely amazing (he also made sure that all were created by HTML5 that's pretty interesting and explanation of separation.) So the point is, it could be new marketing opportunity for creators as you see, besides posting ads.
To me, this is very exciting and always got impressed of what Jobs are thinking.