I don't think you'll see any interlace screens or graphics card support in Symbos for a short while, if ever. On the one hand you have a very specific hardware method for the EP like interlacing, which is great but doesn't fit with the other flavours of Symbos that well in that its not needed on the MSX and is unusable on the CPC. Once you rise above 4 colours the Symbos method is a 16 colour fixed palette. Break this you break all the software.
As cool as Symbos is its still somewhat a lowest common denominator piece of software meaning something running on EP has to work also on the CPC, PCW etc.
As for graphics cards using say the GFX9000 then if anyone builds it and I'm sure Prodatron would support it. But again all these things take time, and I think Prodatron now thinks the SymbosEP is mature enough that he can move back to developing Symbos 3.0 for all its recipiant machines.
The thing that bored Prodatron and forced him to stop developing for 6-7 years last time was people asking for drivers for another of the 1000 FDC's that the MSX seems to have. Covering old ground over and over is not fun and we all need to keep growing and developing new areas rather than maintaining what already exists.
3.0 is Something I think will move Symbos to a new level... especially network support.
I guess what I mean overall is that Symbos is its own standard into which CPC, MSX,PCW and EP can all perform. As an CPC fan its easy to get very specific about features the CPC might be able to do that the others can't.... But symbos isn't CPC its Symbos, and thats its own standard and when I think for developing software for it I'm developing for not just my old friends but new friends here and on MSX.ORG etc