Hi,
Today Atmel has announced the new 8051 device AT89S8253 - 8-bit MSC-51 Microcontroller with 12K Bytes Flash and 2K Bytes EEPROM.

Features:
• Compatible with MCS®-51 Products
• 12K Bytes of In-System Programmable (ISP) Flash Program Memory
– SPI Serial Interface for Program Downloading
– Endurance: 10,000 Write/Erase Cycles
• 2K bytes EEPROM Data Memory
– Endurance: 100,000 Write/Erase Cycles
• 64-Byte User Signature Array
• 4V to 5.5V Operating Range
• Fully Static Operation: 0 Hz to 24 MHz
• Three-level Program Memory Lock
• 256 x 8-bit Internal RAM
• 32 Programmable I/O Lines
• Three 16-bit Timer/Counters
• Nine Interrupt Sources
• Enhanced UART Serial Port with Framing Error Detection and Automatic Address
Recognition
• SPI Serial Interface
• Low-power Idle and Power-down Modes
• Interrupt Recovery From Power-down
• Programmable Watchdog Timer
• Dual Data Pointer
• Power-off Flag
• Flexible ISP Programming (Byte and Page Modes)
– Page Mode: 64 Bytes/Page for Code Memory, 32 Bytes/Page for Data Memory
• Four-level Enhanced Interrupt Controller
• Programmable and Fuseable x2 Clock Option
• Enhanced SPI (Double Write/Read Buffered)

Here is the very prliminary ugly datasheet.

So take it and prepare yourself for future errata! (=

Regards,
Oleg