The DTM version has been upgraded to 4.5

my 8707v's handheld device software is still 4.2

Did RIM stop updating for 8707v or is there any possibility that any handheld device software update for 8707v in the future?

It seems like DTM update was only for Bold and few other BBs..

The update stopped at 4.2 why is that?
Did they officially announce that they are not gonna make any changes to
8707v OS ?