Heise reported today, that Vivane Reding, the current European Commissioner for Information Society and Media, will finally regulate roaming-SMS prices for customers on September 23rd. The cap proposals of the national regulation authorities range between € 0,11 and € 0,15 before tax. However it is expected the limit to be set on the lower end of this range, as well as all 26 commissioners to agree.
After the European parlament' and the memberstates' approval, which is expected for December, the new rates could apply early next year.
So it seems like SMS while roaming will soon cost € 0,15 (with tax) within the EU. That's less than O2 charges me for national SMS on my postpaid contract (I currently would pay € 0,19 if there wasn't Betamax)!