"What U [sic] say is correct"

Please don't do that!
Keep your SMS-speak for your mobile phone, where it belongs:
http://www.8052.com/forum/read.phtml?id=25245&top=

"there are already 256 opcodes from 0x00h to 0xFFh"

255 actually - one is not used ("reserved").
But even though all the opcodes may be used up, that doesn't mean that all the instructions are used up - instructions may be several bytes long, consisting of opcode and operands

So any feature extension (eg, extra ports) which can be added by expanding an operand's range can be added without needing extra opcodes.

In fact, if you look at the 8051's SFR map, you'll see that there are lots of empty SFR spaces - plenty of room for expanded features!