We have been using 87c54, etc for a long time, but now I have the need for 1)more ram and I also want to have flash. It's got to be a pin for pin replacement. I'm using the PLCC44 pkg.
I've looked at derivitives for several days, and I've tentatively settled on the Philips P89C51RC2...RD2 part.
Have a look as well on the P89C66x series up to 8kb internal RAM, up to 8Mb external ram (669)
I understand that with Flash Magic, this part can be programmed using ISP.
correct.
What standard 805x parts are most popular today?
hard to tell, but the Rx2 is probably the only highly capable derivative that is second sourced (Philips, Altera)

Is the Ceibo EB-51X2 a reasonably capable ICE? If not, what are the list members using?
I use it and as to price/perfomance It can not be beat. If you want trace and the really fancy stuff which would probably save me 3-5 hours per year, you need pay 5 times more.

Will the Franklin C compiler support the Philips P89C51RC2 and work with the Ceibo ice?
There is no such thing as a Franklin compiler. There are several brands rebranded as Franklin. If you state your release, someone will probably recognize waht it really is and the your question can be answered or try asking at www.ceibo.com and include your franklin release

Erik