Incorporating more RSS mashing funcionality (a la Yahoo! Pipes) to Imported Feeds

The ability for tumblr to import feeds is crippled by the inability to adjust the incoming content. Though RSS strips away all formatting, certain information is used differently in different contexts.
For example: if I am importing my twitter feed, i don't want each entry to say "SamRoth:" in front of the tweet. Instead, it would be nice to be able to replace that text with "I tweeted" for each post. I did that exact thing using Yahoo Pipes, but it would be nice to bring that funcionality into tumblr itself.