If you are moving from iPhoto to Lightroom, you might need to get yourself accustomed to a simpler form of organization. Outside of faces, which is currently lacking in any automatic form (you can manually add tags for people or families and search by those), it is one of the top requested features for the next release of Lightroom. For the rest, such as events, places, albums, and smart albums, you can use two existing Lightroom features for these: keywords (tags) and smart collections.

Keywording is the primary form of custom tagging, grouping, and searching in Lightroom. You can tag your photos with any keywords, you can create hierarchical keywords, and you can search by keyword sets, partial keywords, or words within the keyewords a photo is tagged with. You can easily add new keywords in a variety of ways (even paint them on with a tool in the library module), so managing them is pretty easy. Unlike iPhoto, which was designed for the average home user who needs more structure and form to their photo organization, Lightroom presents a very simple view of your photos. You don't have any special views.

With Lightroom, you can create things that mirror albums and smart albums...they are called collections and smart collections in lightroom. The concept should be pretty much identical. Collections are groups of images that you manually create from specifically selected photos, while Smart Collections are groups of images automatically created from a variety of search criteria, which can search keywords, EXIF metadata, or any other form of metadata like IPTC. Collections and smart collections can also be nested, allowing a high degree of organization.

As for automatically moving your metadata from iPhoto to Lightroom, you might need to resort to some third-party plugins for this. I found one plugin for iPhoto called Metadata Export for iPhoto 1.1.0 that can export metadata to a variety of formats, including CSV, XML, XHTML, and a flat-file. I am not sure if it can export all metadata, or just some.

For Lightroom, you can import the exported metadata using a plugin called LR/Transporter. It is designed to import from a CSV file, however I am not certain if it supports arbitrary formats, or a specific format. You may need to rework the file exported by the iPhoto Metadata Exporter a bit before importing. LR/Transporter has the ability to match up metadata with images in the Lightroom catalog, and that process is configurable. It should do the trick. You may be able to tweak the CSV file before importing to automatically add keywords for events, faces, and places as well. As for importing albums/smart albums...I am not sure it is possible to import that. You will probably need to recreate your albums as collections in Lightroom.