Back in '09 I wrote a small list of top 10 wishes I had for additions/improvements to Lightroom. AT the time, LR was at version 2.2. When I recently looked back on it, I was struck by how many of these are now getting fulfilled but also by which ones are still on the table. To summarize here are the wishes again from 10 to 1. I'll bold the ones that are now fixed or supplied in LR 4 beta.
10. Faster browsing of previews. While this was sped up a little, it is still one of the main complaints with Lightroom. Scrolling through large sets of images will often result in lagging image preview updates. However a lot of these improvements were negated by overall more complex raw rendering making everything still sort of slow. I call this one still open for fixing.
9. Fool-Proof printing. This was fixed mostly by the printer manufacturers finally getting their act together and updating their drivers to support modern color management. Also any last issues remaining (too dark prints) can now be fixed mostly by the new Print Adjustment sliders in the print panel.
8. Better slideshow module. This has largely remained unchanged and is a huge opportunity for improvement. I don't use it.
7. Lens Correction tools. This is now very well dealt with. Lightroom supplies a lot of lens correction profiles for many main stream lenses and for those remaining you can easily create the profiles yourself (I've done a few and you can download them using Adobe's lens profile downloader tool). In LR4 beta, the lateral chromatic aberration can now be automatically removed for any lens, even those without a profile. It's more effective than the profile-based method supplied in LR 3 in my testing. Still missing is some sort of axial CA correction, but that is far harder to deal with.
6. Facial recognition. Nope not there yet. Aperture does this, Picasa does this, Adobe PS Elements does this. Lightroom should be able to do this (with appropriate privacy controls if needed) but doesn't yet. This feature would be a big timesaver for lots of pro and non-pro users of the software. Obviously for my landscape photography it is useless, but it would be really handy for the family photos. Likewise I'd imagine wedding and event photographers could benefit from this.
5. Geotagging tools. They are now here with the new Map tab. The tools are not yet as good as Jeffrey Friedl's plugins but they represent a hug step forward. Some bugs left in there are that height data is not saved on export and not generated from gpx tracks. If you shoot a lot in the mountains as I do you care about that data.
4. More complex, boolean searching. EDIT: 2/16/11 As Michael Perlov points out below, you can do boolean searches by prefacing search terms with an exclamation mark in the text search field. I am embarrassed that I did not know that as that is a standard boolean operator that I use in programming all the time. It is not complete yet as I don't see an or operator but I think this deserves a bolded heading.
3. Book Making. Yes we finally have this with the built-in book making tool that prints to blurb. Very nice. There is even the promise of future editability of all the templates.
2. Raw pipeline plugins. We don't have these yet, but it is becoming less and less relevant as the built in raw engine is getting so good that I doubt many people still need external noise reduction software or other editing tools. So while this would still be nice, I wouldn't count this against Lightroom right now. Your mileage may vary of course.
1. Soft Proofing. We got this in LR 4b and it is fantastic. It is very well done. In fact better than Photoshop in my opinion. It is very natural and very usable. See here for part 1 and here for part 2 of a great video tutorial from Andrew Rodney. There are a few bugs in the beta version (soft proofing for sRGB doesn't work) but I am confident those will get fixed in the final version.
All in all 5 of my original wishes are fulfilled. 1 is more or less irrelevant, and 1 is really close (the boolean searches). Things are looking great. Of course the best feature of LR 4 beta is the new raw engine. It has to be seen to be believed. Like magic is an apt description.