The syncing is done on the app level: when a new document is inserted into the db that needs to be indexed a background job is launched that insert the document in Solr. This shouldn't be too hard manage if you can write post-save handlers in your model code.
The average document is about 1KB and has about 30 attributes (but only 2-3 of those attributes needs to be index).
Check out riak, they are continuing to develop their full text search engine that integrates with their data store. I have yet to play with it but it looks rather promising and you wont have to deal with trying to bolt on your lucene/solr into couch/mongo.
I do wonder why data store projects such as MongoDB and CouchDB don't start with FTS as the very foundation of everything they do - task one should have been FTS.
I have seen several emails/blogs about mongodb and 10gen musing over FTS. There are a few projects if i am not mistaken that have "bolted on" FTS to mongo but I do not think they have had the same development/LOE as riak search. But with out playing/testing with all those options I can not speak authoritatively on the topic. FTS no doubt will be an emerging factor in the future in the NOSQL landscape IMHO.
I am with thaumaturgy, i hope this fails its just another application of old school thinking. The same thought processes that brought us these horribly designed protocols and their bandaid fixes (dns sec anyone?). Hopefully these old guys will just retire and leave ietf and other such organization that they seem to monopolize to the generation they created this mess for.
10.1 has had 7 release candidate releases so far. Been running them for a while and they don't seem anymore crashy than 10.0 and the GPU acceleration is nice.
Also it would be a great time to upgrade Firefox to the 3.6.4 release candidate for those using Firefox. Plugin process separation... yummo.
Honestly it seems much more like a statement of the facts so you can make a choice. I'd rather also know the RC is unaffected than ONLY know that the current version is vulnerable. Obviously an RC release is not a long term fix, but this is a breaking bug.