I hope no one will using 3G on both the sims
is it soo??? and xperia tipo dual would release in q3..
as far as other oses are concerned they dont have dual sim..
iOS and WP dont even have a normal sim slot..they all use micro sims except perhaps lumia 710..but that is a diffrent matter
nokia has good dual sims but all are feature phones,not smart phones
then there is the spice stellar mi-425 with a 1 ghz proccy,3.8 inch screen,5 mp cam which comes with dual sim..spice promises ICS for this
but spice handsets have an earpiece problem wherein the call quality deteriorates slowly(personal experience)
there is also karboon a9 but that again is personal choice not a unanimous decision
then there is the desire vc also
surprisingly it has 5 stars on flipkart but the specs are not very pleasing
it is completely absurd to spend anything over 18k on a single core 1 ghz processor phone with/without ics and with/without dual sim with only 512 mb ram and outdated adreno 200 gpu for the price
your best bet IMO would still be the xperia tipo dual.you wouldnt find a better specced phone with ics out of the box at its price
rgding s duos go for it only if priced @ the same price as the normal galaxy s i.e 18k