Virginia's current system resembles a "notice and demand" system because Virginia law requires a certificate of analysis be filed 7 days in advance of a hearing - giving the accused notice that the government intends to rely on the affidavit.  However, as a practical matter 7 days doesn't give enough time for a witness to be subpoenaed without a case being put off to a later date.  In fact, Virginia courts won't even honor a subpoena request submitted so close to the court date.  Another Virginia law places the burden on the accused at least to provide notice of a desire to have a witness present, and perhaps to subpoena the witness, and prior to the decision in Melendez-Diaz, Virginia courts had ruled the defendant's failure to do so amounts to a waiver of the right to confront the prosecution witnesses.  However, Virginia courts have not been precise when discussing the issue and it is unclear what an accused must do in Virginia to assert the right to confront witnesses.  In some places Virginia opinions suggest the accused need only say the witness must be brought, while in other places Virginia courts seem to suggest the accused actually needs to subpoena the witness. 

Since shifting the burden to subpoena the witness to the accused and deeming the failure to do so a waiver has been rejected and overruled by the Supreme Court of the United States, it will be interesting to see how Virginia courts respond.  Perhaps the Virginia General Assembly will pass a new law setting forth specific time frames within which the government lawyers must provide notice of the intent to use an affidavit, and the lawyer for the accused must object and assert the desire to confront the witnesses.  Perhaps Virginia courts will simply re-interpret the current statute to mean that an accused must notify the prosecuting attorneys of an objection to the use of an affidavit or certificate or analysis without the witness being present and clearly state the burden of producing the witness remains with the Commonwealth.