Information is hard to find about the progress of this program, but here is a report on monetary operations (under the "Ad-Hoc" tab) related to the liquidity absorption of these purchases. Excerpt:
......A variable rate tender with a maximum bid rate of 1.00% will be applied and the ECB intends to absorb an amount of EUR 61 billion. The latter corresponds to the size of the Securities Markets Programme, taking into account transactions with settlement at or before Friday 10 September, rounded to the nearest half billion. As the settled SMP transactions last week were of a volume of EUR 237 million, it happens that the rounded settled amount - and the intended amount for absorption accordingly - remains unchanged at EUR 61 billion.......So it looks like the ECB has so far purchased e61B ($79B) since mid-May. I have not been able to find any details about securities purchased or country of original issue, but the general suspicion is that some of the European countries with smaller economies that have larger, persistent external deficits were/are having problems with issuing their government securities and the ECB has stepped up as effectively a buyer of last resort. Three countries perhaps in this category are Greece, Ireland, and Portugal.
How does this $79B equivalent of purchases compare to the stock and flows of government securities of these three countries? Data from an OECD website here.
Total Government Debt (Stock) of:
So the $79B of purchases represent 10.8% of the total government debt outstanding of these countries combined.
Total YoY ('08 to '09) Government Debt net issued (Flow):
Accordingly this $79B of ECB purchases represents 60% of this recent flow measure.
If this ECB program is indeed focused on the liquidity of the government securities of basically just these three countries, it is probably a substantial factor in the ability of these countries to issue or at least issue at reasonable rates.