Dirq, thanks for you reply.  I actually found a better solution for basic row selection using the row selection event provided by the igGridSelection module.  I hadn't known to look there before.   To wire it it I do something like the following where onRowSelection is a public method on my viewmodel:

<table id="grid1" data-bind="igGrid: {
[other options...],
features: [
{
name: 'Selection',
mode: 'row',
multipleSelection: false,
rowSelectionChanged: onRowSelection
},
{name: 'Updating', enableAddRow: false, enableDeleteRow: false, editMode: 'none' }

]
}"></table>

I'm doing it, but it's messy right now until IG puts out a better way. (igGrid, IgniteUI 13.1.20131.2143)

I put my igGrid initialization in a function like this:

function loadControls(viewModel){/*init the grid in here so i have access to the view model*/}

I then use the RowSelectors feature and handle the checkBoxStateChanged event like so:

checkBoxStateChanged: function (evt, ui)
{
	//Knockout ViewModel, but it could just be an array
	var boundModel = viewModel.selectedItems;
	//the record in the grid					
	var r;

	if (ui.isHeader)
	{
		//clear my viewModel for later re-adds
		boundModel.removeAll();

		if (ui.grid.selectedRows().length > 0)
		{
			if (ui.state == 'on')
			{
				for (var i = 0; i < ui.grid.selectedRows().length; i++)
				{
					r = ui.grid.findRecordByKey(ui.grid.selectedRows()[i].id);
					if (r != null)
						boundModel.push(r);
				}
			}
			return;
		}
	}

	//my users could change the multiselect option on the fly
	if (viewModel.allowMultipleSelections() === false)
		boundModel.removeAll();

	r = ui.grid.findRecordByKey(ui.rowKey);
	if (r != null)
	{
		if (ui.state == 'on')
			boundModel.push(r);
		else
			boundModel.remove(r);
	}
}

To complete the "bindings" I also handle the rowsRendered event so it can select on paging, etc:

rowsRendered: function (evt, ui)
{
	//Knockout ViewModel, but it could just be an array
	var boundModel = viewModel.selectedItems;
	var gridId = ui.owner.id();

	//For each of my saved selected items
	//select the checkbox on the grid
	for (var i = 0; i < boundModel().length; i++)
	{
		//the item's primary key
		var key = boundModel()[i].Id;
		
		for (var x = 0; x < ui.owner.rows().length; x++)
		{
			//the row contains the key on an attribute data-id="primarykey"			
			var rowKey = ui.owner.rows()[x].getAttribute("data-id");
			if (key == rowKey)
			{
				$('#' + gridId).igGridSelection('selectRow', x);
			}
		}
	}
}

I know it's not clean, but it gets the job done.

I'm also looking for a way to bind the selected rows with a knockout observable array.