Couple of answers in one.
Jim: I can't comment on what Apple will support in the future. It's best to ask Apple if they will support MDM as it uses a public standard (OWM-DM).
bday: This would really be a separate conversation but if they are "screen scraping" OWA then there is little Exchange can do there. From an admin stance you can block those requests at your firewall looking at the IP address they are coming from (as they use an aggregating server) or you could look at the user-agent string. This is the same thing BlackBerry Internet Service (BIS) does so if this is a concern you might want to look at how your company deals with that kind of access to your Exchange Server.
Roman: Task sync is in the protocol, it is up to Apple to choose what features they implement.
TJ: Remote wipe form the Exchange Admin/OWA side is the same as any other EAS-enabled device. From the device side you would have to ask Apple if they are using encryption and if they do a secure wipe. (note: their Enterprise deployment guide says the wipe can take over an hour so that might give you an indication but you should ask Apple for certain.)