Pablo, thanks for the presentation. While my qualifications to answer this are 0 getting to listen to Upayavira talk this week (the last Apache mentor if I'm not mistaken) make me feel the answers to 1 and 2 are easy to answer.
1.) Upayavira communicated very fervently that there just isn't enough oomph in wave's development. Every year around the time that the retirement conversation is brought up, activity similar to this starts brewing and then it all dies down in a few months. From this perspective "Does SwellRT tackle current Wave problems?" The answer is unequivocally yes, SwellRT is a more actively maintained fork of Wave and given the slowing/slowed pace of Wave *a merge with SwellRT is likely the only way to save this project*. 2.) I would also like to bring up another point Upayavira made, "Communities are built around good ideas and bad code." Running with that I thing that good ideas attract tinkerers and 'people with ideas' that could eventually become 'contributors with ideas'. In some senses SwellRT splinters Apache Wave in a way that developers on this mailing list have been alluding to for a while. The client side code is not well understood and is definitely in the way of the server. SwellRT has a more general goal of supplying a server that is capable of powering a front-end like the original vision of google wave. This means that merging with SwellRT would force a separation of the client and server and allow for people with interests in either a front or back end to work in tandem. This seems like an ingenious way to attract more people; anyone with an interest in the backend technology OR a way to use said technology in an application could be a potential contributor. Unless I'm mistaken it seems like SwellRT offers a set of features that could be classified as a superset of Wave's features. So, it seems like most or all of SwellRT would be at home in Wave. Pablo also reasonably stated that he'd prefer to work in one project. As for me, as soon as a direction is clear I would love to talk to someone actively maintaining/writing code so I can help them contribute to whichever code survives in whatever way possible.