I am a late convert from slide film to digital (and still continue shooting slides, by the way).
For me Lightroom is wonderful. I have very little experience in PhotoShop, and it saves me dealing with that labyrinth of menus and functions, which are - as I heard - due to a long history not always very logically placed.
Lightroom is very intuitive and lets you concentrate on photography.
It is great to select the images you want and to discard the rest.
It also displays images in a much higher quality than other software. (Silkypix' photo browser, which comes with the Pentax cameras, and the photo laboratory, may produce results, but for a photographer these are just awful pieces of software, unintuitive, poor display quality of the images).
In Lightroom, where I can quickly make and compare versions (called "snapshots"), for example, I can focus on the essential and fascinating.
After all, this is version 1 (and an upgrade, free for early adopters, as I read on this forum, is on the way) is truly workable. Those unhappy with LR: haven't you ever worked with really awful software? endless sub menus. Unintuitive. Deflecting your creativity by needing too much attention.
I can understand the frustration about the size limitations, and I hope this will be corrected in future upgrades.
Well, I also wish the keyword functions to be a bit more accessible.
But, to return what pleases me: the design of the software. The working space a software creates on your screen is like a face you look into. It is a very elegant design, and I like the face - it is like an architecturally well built and designed house you like to walk into.
It is, in its intuitiveness, a great prolongation of the joy of photography, making the lightroom work (opposite to the traditional darkroom work) a joy, not a chore.
And I guess this is the main point.
Speed, picture size limitations, a better working library: this all will come, but the basic structure is sound and good.