Any Yahoo Pipes true substitute out there ?

The future loss of Yahoo Pipes in August this year will be a major blow to the monitoring/research community and also web site authors looking for selected content. Its ability to combine and filter multiple RSS feeds into one feed remains unique among free hosted services. This post will focus on how we could replace Yahoo Pipes for these functions .
So I went looking for substitutes. I mean, real ones : as simple as Pipes. For instance, they should have a graphic user interface (GUI). (...)