Two of T-Mobile’s Samsung devices have dropped $50 today, adding to their Android appeal. The Galaxy S series T-Mobile Vibrant now runs $149.99 while the 7-inch Galaxy tab sells for $349.99, after rebates of course.  It will be interesting to see if these are short term price breaks or if they are here to stay.  We imagine the Vibrant was dropped to help differentiate between the Nexus S, which will be supported by the carrier starting tomorrow.