First reactions to Brown's speech
YouGov have an instant reaction poll to Brown's speech. This was a survey of 673 people who watched Brown's speech.
The topline is that they liked it. 33% thought it was an excellent speech, 30% good, 22% fair, 11% poor and 4% bad. Their opinion of Brown has also improved since a few days ago, his net approval rating amongst these people was minus 24 a couple of days ago, now it it zero, so a big jump.
However, it's important to remember that these are people who watched Brown's speech, rather than a representative sample. Almost by definition, the majority of an actual representative sample wouldn't have watched the speech, so wouldn't be able to give any sort of verdict yet. People who watched his speech are likely to be a lot more politically aware, a lot more well disposed towards Labour to start with (I suspect you're more likely to watch the speech of a party you like), and hence probably more receptive to Brown's message.
The real effect of Brown's speech will what difference it makes to the vast majority of people who see only clips of it on the 10 o'clock news, or hear it only through the prism of the newspapers tomorrow morning. Next voting intention figures will be at 5.05pm tomorrow, so we'll see then how much of a boost it gives Labour.