The Amoi N820 (Big V) seems to be the first MTK MT6577 based phone to get an update from ICS to Jelly Bean (Android 4.1). As Amoi most probably did not do all the porting by themselves I am sure MTK will offer this release to other companies, too. I suspect most MT6577 phones run a mostly unmodified system built from MTK. Thus a major wave of Android 4.1 updates for these phones might follow close after the roll-out by Amoi. While we wait for this to happen, take a look at the first pictures showing Jelly Bean on the N820.