Spoiler Level: High
This is the story that, if you don't watch Sarah Jane Adventures, you're still going to watch if you're a Doctor Who fan. And really, this is the one you definitely should see.
UNIT shows up on Sarah Jane's doorstep and says a group of aliens have delivered the Doctor's body, and are taking her to a special UNIT facility for his funeral. While there, Sarah Jane gets to meet the Doctor's previous companion from UNIT, the one and only Jo Grant! (Or Jo Jones, rather, after the events of her departure story, "The Green Death.") It's not long until the Doctor crashes his own funeral and all the running starts!
"Death of the Doctor" works even better than the Doctor's previous guest appearance, last year's "The Wedding of Sarah Jane Smith." Just like last year, the Doctor himself doesn't show up until towards the end of Episode 1, but it works a little better here because (1) Matt Smith actually gets to do more that just shout one line before the credits roll, (2) even if the Doctor himself isn't in the first 20 minutes or so, the action is all about him, so his presence is still felt, and (3) we get to see Jo right away, which is probably even more of a thrill than getting to see the Doctor. I know I'll see Matt Smith again in December; this is the first time I've seen Jo since she left the show in 1973, and I may never see her again!
In some ways she's the same old Jo, all enthusiasm and smiles. And in other ways she's grown so much; like Sarah Jane, she's become the one in charge now, traipsing all over the world with her husband, their children, and their grandchildren. (And let me just also mention here how happy I am that she and Professor Jones are still happily married!) Jo's brought her grandson, Santiago, who fits in with Clyde and Rani wonderfully. I didn't want the show to just drop in a new male lead to replace Luke like they did with Rani being introduced right on Maria's heels, but I have to admit, if they were going to replace him, the grandson of Jo Grant would be a great choice.
Russell T Davies excels at character pieces, and that's exactly what this is; even the bad guys motivation is an angle to feature as many memories as possible about the Doctor! We even get some wonderful little bits of news as Sarah Jane tells Clyde and Rani what she's learned about Ian & Barbara, Ben & Polly, Tegan and Ace since they left the TARDIS! (Ian & Barbara's especially made me smile, and Ace's made me breathe a sigh of relief I think I've been holding since I saw Mindgame Trilogy.)
Not that it's perfect; some of the special effects are surprisingly below current standards. There's a very obvious matte-painting for the UNIT headquarters, and some very obvious puppeteering for the aliens, which is a bit of a surprise considering how well the special effects have looked on every Doctor Who related program since the show's return. I don't know if it was done "old-school" deliberately to give it more of a classic Who feel, or if the money just wasn't there, or if it just looked worse to me because I saw it on a 58" TV! Personally, I'm going to go with the "old school" theory, at least for me. And I actually kind of prefer puppets to CGI.
Aaaannd, since it was a very nostalgic, memory-oriented episode, it made for a great lead-in to Whofest 2010!