I just put up a post on my blog about this so you can read the longer form version there.
I like lightroom and there is no doubt there are some cool features in the new version that make a significant difference to LR3 - not to mention the new processing algorithms.
But the one thing LR still misses is portability.
Having bought the macbook air last year - i am seriously toying with the idea of just using the iPad for photography weekends and short away from home assignments and even leaving the MBAir on the desk at home. It seems I could do so much with it with just some minor functionality.
The iPad doesn't have enough grunt for high end processing.
The Air doesn't have enough space for long term storage.
Moving stuff around the file system and across catalogues is still pretty clunky.
My main feature wish for the Lightroom Santa is that next release brings me that all important mobility !!!!