Archaeologists believe that a series of military artefacts unearthed in Chichester, Sussex, and dated decades before the AD43 date will turn conventional Roman history on its head.
That tweaked something in the old noggin and I realized that one of the 'series' of artifacts is a strange sword piece found in a ditch in the Fishbourne Roman Palace excavations. At the FRP official site, there are a pile of documents on the Research page (pdf) one of which details excavations of the 2002 season. On page four of that document, you'll see a photo of the copper alloy sword thingy which, at the time of publication, was described as the "fitting from a Roman wooden sword scabbard". I've been trying off and on to figure out where on a scabbard this thing would go (where the sword goes in?), but think that, on its own, this item is rather scanty as far as evidence of an earlier invasion goes (it's apparently Augustan in date). So, now we wait to see what other items form the "series".
Even so, it seems very much a leap to go from one or two artifacts to claims of 'earlier invasion'. I don't think anyone would deny that there was probably a continuous trade presence with Rome in one form or another from the time of Julius Caesar's invasion (and one which would probably account for every artifact which Time Team will bring up). FWIW, there are also a couple of interesting conference summaries on that aforementioned FRP research page and the Sussex one includes quite a bit of info on the continuous trade with the continent ... I think it is probably salutory also to remember that we have recently had in the news research which indicates that the Vikings had access to 'German arms dealers'; just because a Roman artifact is found in a pre-invasion context doesn't mean that a Roman put it there.