from http://download.mikrotik.com/newsletter24_mum.pdf
RouterOS 5
The new RouterOS version was announced at the
MUM. Launch of first public beta is expected within
two weeks (ie. end of March 2010).
and it is March 31 
still waiting
private testing began long time ago, you missed it 
we will release it in a few days, don’t worry
I know . i mean public tests .
It has some features which we could not ignore . hurry up please
Just installed the PUBLIC beta
Up just fine…