Some very ridiculous rumours

Ok, I was interested in any REAL INFO on what was going to happen with the Christmas special this year, but instead I found some very ridiculous rumours, courtesy of Scyfilove
Here are some ok ones that have been confirmed by BBC:

1. Michael Gambon
2. Katherine Jenkins

But here are some absolutely strange ones:

• Matthew Waterhouse will be playing the ghost of Adric, a companion who died!
• Nick Briggs will be voicing ...wait for it... the Cyber daleks! (is this half dalek, half cyberman?)

There are also some uncredited roles (that could mean they appear in flashbacks...)

• John Simms as the Master 
• Alex Kingston as River Song (maybe something might be revealed about her mysterious line in the last episode about how 'when they next meet that's when everything changes'?
• Also (take a deep breath before reading this...) TOM BAKER as THE DOCTOR!

So what do you think of these then? True or just attention grabbing?