hi,

Philips IC's can be programmed directly via the UART. for atmel you need the SPI etc.

Not correct. If we talk about "classic" MCU51/52 from Atmel then yes, these parts has been programmed with parallel programmer (all) or ISP-via-SPI (most of them).
But if we talk about "second-generation" Atmel derivatives then you are wrong. Most of them are in-system programmable with bootloader built-in. Some of them are programmed via UART, some - via USB, anothers - with CAN. Moreover, user may create own bootloader and it is smart enough to implement even programming over network. For example, here we have CAN-network in which the software of any point (based on AT89C51CC03) may be updated from master node over network. It is useful feature by which we need not with any manual work at remote point to do its software update.

Regards,
Oleg