PDF/A-2, according to a news item from Luratech, has been finalized and will be published as a standard in early 2011. (But see the comments.) Some more information (PDF) is available from the PDF/A Competence Center. PDF/A-1, which is based on PDF 1.4, will continue to remain a valid standard. PDF/A-2 is based on ISO 32000-1, aka PDF 1.7.