The DPP seized on the busing plan as an "obvious" example of vote buying and is suing. It may be illegal by Taiwanese standards (see article 86 of the Presidential Election and Recall Law). I know this is perfectly legal in the US. As far as I know, no official word from the CEC on this yet. As a result, the KMT apparently canceled this busing plan (according to Su's quote in that article, but that's not clear from other sources yet).
Also of note, Jonathan Adams report on the DPP's loss of the youth vote, which, anecdotally, seems true to me. But I also think they're less likely to vote this time around, so I'm not sure how this will really effect things.
And that's a pretty significant portion of the 17 million or so eligible voters.
According to the United Daily News poll, those in their 20s are also the least likely age group to vote Saturday.
There are 3.67 million people in Taiwan between the ages 20 and 29, according to
Taiwan's Ministry of the Interior -- all eligible to vote.