If your referring to DASS it wont be operational until 2017/2018 at the earliest
although enhanced beacons may well be hitting the marketplace in the next year or so.
Either way there is full compatibility with existing PLB's so really no reason to
wait if contemplating a Beacon purchase.
IMO they should be on everyone's lifejacket
(always assuming you wear one of course
Even with a Beacon there is room on the boat for a flare - laser and good old flash and bang.
In a crowded Solent I could see a case where a flare may get peoples attention pretty quickly in an emergency.
Good safety kit costs money. If you need to use it, you will be very pleased you paid for it.
The more I read about SAR, the more I understand that there is still an element
of luck and chance in all rescues, and gradually technology
is being developed to try and remove that chance factor.
As the OP was asking about training,
giving yourself effective safety kit and training should be a priority.
I endorse any kind of training and technology
that will make our passion for boats safer and stress free.