Thanks to our own SinghNSK for sending this in. Nokia store links reveal much about upcoming Asha 500, 502 and 503 and 503 dual-sim devices.
According to the details revealed, Asha 503 is 3G device while all others like Asha 500, 502 etc are 2G device just like Asha 501. RM-920 is revealed to be Asha 503 single sim, RM-921 is Asha 502 and RM-922 is Asha 503 dual-sim and if you remember we have seen RM-922 passing through FCC with 3G bands.
Only downers may be that display resolution for even Asha 502 and 503 is 240 x 320 similar to Asha 501.
Only for Asha 503, 3G is seen in the details,
This does confirm that Nokia may actually announce all three Asha 500, 502 and 503 on October 22nd in Nokia World event.