I think browsing by annotations is a good idea. If this is a faceted browsing it could also be useful if acting as a filter for the list of ROs displayed, which may be provided by searches based on the upper general textbox. Because we are searching ROs and not their components, I think that the elements present in the browsing should be attributes for annotations on the whole RO (this is another reason for demanding the possibility of annotate the whole RO and not only the components). These attributes may be in a first time among the following list that I propose: keywords, date, web services, data providers, data types, creator, etc.. Whatever the list of attributes chosen, all of them should allow for a faceted filtering, that's why attributes like title or notes do not seem to be well placed in this list.
Concerning the list of ROs displayed in the homepage, I would also add the top ten most cited and most popular :)
I would go on a more "à la MyExperiment" approach, where all possible information on the RO is displayed for each element in the list: title, keywords, size, authors, ratings, I&A evaluation score, downloads, versions, created, updated, numbre of comments, citations and reviews, etc..
Personally, I find a very useful feature in MyExp to display a thumbnail of the graphical representation of the workflow. In our case, because we are dealing with ROs, it would be useful to display the thumbnail of every workflow contained in an RO.
An RO page
I find this page is already very developed and near to my expectations :)
I find two main kinds of RO components: files and processes, represented with the file icon and engine icon respectively. Files maybe input and output datafiles, bibliography, notes on text files. Processes may be the digital workflows, local scripts and web services.
External components like web services or data archives may be represented outside the RO folder with the web link icon. If I picture the RO content as a filetree structure, with components seen as files, I think external components should not be represented inside a "folder".
Not all the components will have a Title, in fact I think that most of them will not have a Title. That's why I suggest to display the filename instead when the Title is not available.
Concerning the annotations block, though I may provide a list of attributes and feedback , I think this is not very relevant for the functionality of the web appli.
 Users requirements on annotations