I personally seriously doubt that there will be a 2.4L V-8. Of all the manufacturers, BMW are SPECIALLY opposed to this new engine formula. As well, it will be near impossible for the teams to start developing 2.4 V-8s for 2005 Season, hence, at best, if the new reg DOES pass throguh (again, which i seriously doubt), the earliest at which the engine regs would atleast be implemented would be 2006. As planned, therefore, the engine designation, whether it be a 3 V-10 or a 24 V-8 would be the P86.
If the rule changes do follow through, though, i believe the greatest beneficiaries would be Mercedes seeing as thogh they have such a strong V-8 base from their CLK's in the DTM series.