It seems that MediaTek has been working on a new chipset - MT6575 - as a response against Qualcomm's MSM7227A. It's said that it will feature a single core ARM Cortex™-A9 processor clocked at up to 1 GHz and will also support HSPA+. By comparison, MT6573 is much inferior, because the used chip integrates an ARM11™ processor clocked at only 650 MHz. On the modem part, MT6573 chipset only supports data connections up to HSPA (speed of 7.2 Mbps / 5.76 Mbps).
It's expected that the first MT6575 based smartphone prototypes start appearing after the upcoming Chinese New Year. Let's wait then!