Not a chance. Dreamcast emu is a long, long way off yet.
They're just about cracking Model 1 and 2 emulation at the moment and that requires top spec machines like yours so I doubt they'll have DC emulation for another 4 or 5 years.
If you get an x-arcade pcb (you can order them separarely from the entire stick) they supply (admittedly kind of expensive) adaptors so you can connect your DC, PS2, GC and whatever consoles come out in the 256 generation to your cabinet as well as MAME. If you're interested in going for a multi-console compatable cabinet its worth thinking about.
I've got Ikaruga, Soul Calibur, Virtua Tennis for my DC. There are some fantastic arcade games available really, really cheap at the moment so i'd recommend anybody to buy one. They're only 20 quid on e-bay.
I got Bangai-O by Treasure this week. It's bloody fantastic. Like Robotron with even more action. Only cost me a fiver as well.