In this new release (Aspose.Pdf.Kit for .NET v.3.1) you can import comments or annotations from PDF files or XML. Another feature for crating PDF stamp with user defined appearance is also supported.

More about Aspose.Pdf.Kit for .NET

Aspose.Pdf.Kit is a .NET component to edit existing PDFs supporting window forms and ASP.NET applications. You can add digital signatures or encrypt/decrypt a PDF file. It supports XFA, adding CJK font in form field, bookmarks, PDF stamp creation, AcroForm, adding watermark or logo, extracting or adding images & text, append pages and converting PDF file to TIFF, BMP, PNG & JPG image formats. It enables you to concatenate PDF files and allows adding or setting XMP Metadata to an existing PDF.

For more info follow this link: http://www.aspose.com/community/blogs/aspose.pdf.kit/archive/2008/05/16/aspose-pdf-kit-for-net-3-1-0-0-released.aspx